Previously, the comparison code would loop through segments up to the
longest of the two versions being compared. However, this is inefficient
because once one version has more segments than the other we can do a
lot less work.

This commit optimizes the differing segment length case by specializing
the logic once the iteration has passed the shorter of the two segment
lengths. At this point we only need to continue looking at the longer
version's segment, and we know that any String encountered means the
version is less than (pre), and any non-zero Integer means the version
is greater than.

Benchmark:

```
{
  first: [Gem::Version.new("1.2.3"), Gem::Version.new("2.2.3")],
  second: [Gem::Version.new("1.2.3"), Gem::Version.new("1.3.3")],
  third: [Gem::Version.new("1.2.3"), Gem::Version.new("1.2.4")],
  length: [Gem::Version.new("1.2.3"), Gem::Version.new("1.2.3.4")],
  left_s_second: [Gem::Version.new("1.a.3"), Gem::Version.new("1.2.3")],
  left_s_third: [Gem::Version.new("1.2.a"), Gem::Version.new("1.2.3")],
  right_s_second: [Gem::Version.new("1.2.3"), Gem::Version.new("1.a.3")],
  right_s_third: [Gem::Version.new("1.2.3"), Gem::Version.new("1.2.a")],
  left_s_length: [Gem::Version.new("8.0.1.pre"), Gem::Version.new("8.0.1")],
  right_s_length: [Gem::Version.new("8.0.1"), Gem::Version.new("8.0.1.pre")],
  both_s: [Gem::Version.new("8.0.2.pre1"), Gem::Version.new("8.0.2.pre2")],
}.each do |name, v|
  puts "== #{name} =="

  raise name unless v[0].fast_comp(v[1]) == (v[0] <=> v[1])

  Benchmark.ips do |x|
    x.report("fast") { v[0].fast_comp(v[1]) }
    x.report("original") { v[0] <=> v[1] }
    x.compare!(order: :baseline)
  end
end

== first ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   208.555k i/100ms
            original   199.789k i/100ms
Calculating -------------------------------------
                fast      2.075M (± 6.0%) i/s  (481.93 ns/i) -     10.428M in   5.055818s
            original      2.045M (± 3.9%) i/s  (488.94 ns/i) -     10.389M in   5.090034s

Comparison:
                fast:  2075002.8 i/s
            original:  2045227.4 i/s - same-ish: difference falls within error

== second ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   192.395k i/100ms
            original   183.000k i/100ms
Calculating -------------------------------------
                fast      1.892M (± 3.8%) i/s  (528.62 ns/i) -      9.620M in   5.094104s
            original      1.824M (± 3.5%) i/s  (548.11 ns/i) -      9.150M in   5.023163s

Comparison:
                fast:  1891722.2 i/s
            original:  1824435.3 i/s - same-ish: difference falls within error

== third ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   172.788k i/100ms
            original   162.934k i/100ms
Calculating -------------------------------------
                fast      1.719M (± 9.0%) i/s  (581.72 ns/i) -      8.467M in   5.025861s
            original      1.638M (± 3.6%) i/s  (610.36 ns/i) -      8.310M in   5.080344s

Comparison:
                fast:  1719042.9 i/s
            original:  1638389.6 i/s - same-ish: difference falls within error

== length ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   191.741k i/100ms
            original   155.952k i/100ms
Calculating -------------------------------------
                fast      1.920M (± 3.9%) i/s  (520.74 ns/i) -      9.587M in   5.002328s
            original      1.576M (± 6.2%) i/s  (634.42 ns/i) -      7.954M in   5.072507s

Comparison:
                fast:  1920362.1 i/s
            original:  1576240.9 i/s - 1.22x  slower

== left_s_second ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   176.441k i/100ms
            original   164.879k i/100ms
Calculating -------------------------------------
                fast      1.609M (± 7.3%) i/s  (621.51 ns/i) -      8.116M in   5.083414s
            original      1.620M (± 8.3%) i/s  (617.43 ns/i) -      8.079M in   5.028525s

Comparison:
                fast:  1608994.8 i/s
            original:  1619606.5 i/s - same-ish: difference falls within error

== left_s_third ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   160.562k i/100ms
            original   152.799k i/100ms
Calculating -------------------------------------
                fast      1.591M (± 3.6%) i/s  (628.40 ns/i) -      8.028M in   5.052029s
            original      1.528M (± 3.6%) i/s  (654.31 ns/i) -      7.640M in   5.007526s

Comparison:
                fast:  1591334.1 i/s
            original:  1528320.6 i/s - same-ish: difference falls within error

== right_s_second ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   135.938k i/100ms
            original   132.907k i/100ms
Calculating -------------------------------------
                fast      1.367M (± 1.2%) i/s  (731.77 ns/i) -      6.933M in   5.074030s
            original      1.320M (± 2.4%) i/s  (757.35 ns/i) -      6.645M in   5.036155s

Comparison:
                fast:  1366548.7 i/s
            original:  1320386.4 i/s - same-ish: difference falls within error

== right_s_third ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   129.971k i/100ms
            original   123.802k i/100ms
Calculating -------------------------------------
                fast      1.273M (± 4.1%) i/s  (785.25 ns/i) -      6.369M in   5.011805s
            original      1.215M (± 1.8%) i/s  (823.04 ns/i) -      6.190M in   5.096330s

Comparison:
                fast:  1273487.0 i/s
            original:  1215002.9 i/s - same-ish: difference falls within error

== left_s_length ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   211.093k i/100ms
            original   155.784k i/100ms
Calculating -------------------------------------
                fast      2.120M (± 1.9%) i/s  (471.63 ns/i) -     10.766M in   5.079336s
            original      1.565M (± 6.7%) i/s  (638.87 ns/i) -      7.789M in   5.007522s

Comparison:
                fast:  2120296.1 i/s
            original:  1565258.0 i/s - 1.35x  slower

== right_s_length ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   213.977k i/100ms
            original   142.990k i/100ms
Calculating -------------------------------------
                fast      2.154M (± 1.3%) i/s  (464.15 ns/i) -     10.913M in   5.066124s
            original      1.446M (± 1.8%) i/s  (691.75 ns/i) -      7.292M in   5.046172s

Comparison:
                fast:  2154455.3 i/s
            original:  1445607.9 i/s - 1.49x  slower

== both_s ==
ruby 3.4.2 (2025-02-15 revision https://github.com/rubygems/rubygems/commit/d2930f8e7a) +PRISM [arm64-darwin23]
Warming up --------------------------------------
                fast   154.903k i/100ms
            original   131.011k i/100ms
Calculating -------------------------------------
                fast      1.515M (± 4.0%) i/s  (659.97 ns/i) -      7.590M in   5.019890s
            original      1.280M (± 5.3%) i/s  (781.28 ns/i) -      6.420M in   5.035387s

Comparison:
                fast:  1515223.3 i/s
            original:  1279957.8 i/s - 1.18x  slower
```

https://github.com/rubygems/rubygems/commit/7195e77152