This PR fixes an AST and token incompatibility between Parser gem and `Prism::Translation::Parser`
for dstring literal:

```ruby
"foo
  #{bar}"
```

## Parser gem (Expected)

```console
$ bundle exec ruby -Ilib -rparser/ruby33 -ve \
'buf = Parser::Source::Buffer.new("example.rb"); buf.source = File.read("example.rb"); p Parser::Ruby33.new.tokenize(buf)'
ruby 3.3.0 (2023-12-25 revision https://github.com/ruby/prism/commit/5124f9ac75) [x86_64-darwin22]
[s(:dstr,
  s(:str, "foo\n"),
  s(:str, "  "),
  s(:begin,
    s(:send, nil, :bar))), [], [[:tSTRING_BEG, ["\"", #<Parser::Source::Range example.rb 0...1>]],
[:tSTRING_CONTENT, ["foo\n", #<Parser::Source::Range example.rb 1...5>]],
[:tSTRING_CONTENT, ["  ", #<Parser::Source::Range example.rb 5...7>]],
[:tSTRING_DBEG, ["\#{", #<Parser::Source::Range example.rb 7...9>]],
[:tIDENTIFIER, ["bar", #<Parser::Source::Range example.rb 9...12>]],
[:tSTRING_DEND, ["}", #<Parser::Source::Range example.rb 12...13>]],
[:tSTRING_END, ["\"", #<Parser::Source::Range example.rb 13...14>]], [:tNL, [nil, #<Parser::Source::Range example.rb 14...15>]]]]
```

## `Prism::Translation::Parser` (Actual)

Previously, the AST and tokens returned by the Parser gem were different. In this case, `dstr` node should not be nested:

```console
$ bundle exec ruby -Ilib -rprism -rprism/translation/parser33 -ve \
'buf = Parser::Source::Buffer.new("example.rb"); buf.source = File.read("example.rb"); p Prism::Translation::Parser33.new.tokenize(buf)'
ruby 3.3.0 (2023-12-25 revision https://github.com/ruby/prism/commit/5124f9ac75) [x86_64-darwin22]
[s(:dstr,
  s(:dstr,
    s(:str, "foo\n"),
    s(:str, "  ")),
  s(:begin,
    s(:send, nil, :bar))), [], [[:tSTRING_BEG, ["\"", #<Parser::Source::Range example.rb 0...1>]],
[:tSTRING_CONTENT, ["foo\n", #<Parser::Source::Range example.rb 1...5>]],
[:tSTRING_CONTENT, ["  ", #<Parser::Source::Range example.rb 5...7>]],
[:tSTRING_DBEG, ["\#{", #<Parser::Source::Range example.rb 7...9>]],
[:tIDENTIFIER, ["bar", #<Parser::Source::Range example.rb 9...12>]],
[:tSTRING_DEND, ["}", #<Parser::Source::Range example.rb 12...13>]],
[:tSTRING_END, ["\"", #<Parser::Source::Range example.rb 13...14>]], [:tNL, [nil, #<Parser::Source::Range example.rb 14...15>]]]]
```

After this correction, the AST and tokens returned by the Parser gem are the same:

```console
$ bundle exec ruby -Ilib -rprism -rprism/translation/parser33 -ve \
'buf = Parser::Source::Buffer.new("example.rb"); buf.source = File.read("example.rb"); p Prism::Translation::Parser33.new.tokenize(buf)'
ruby 3.3.0 (2023-12-25 revision https://github.com/ruby/prism/commit/5124f9ac75) [x86_64-darwin22]
[s(:dstr,
  s(:str, "foo\n"),
  s(:str, "  "),
  s(:begin,
    s(:send, nil, :bar))), [], [[:tSTRING_BEG, ["\"", #<Parser::Source::Range example.rb 0...1>]],
[:tSTRING_CONTENT, ["foo\n", #<Parser::Source::Range example.rb 1...5>]],
[:tSTRING_CONTENT, ["  ", #<Parser::Source::Range example.rb 5...7>]],
[:tSTRING_DBEG, ["\#{", #<Parser::Source::Range example.rb 7...9>]],
[:tIDENTIFIER, ["bar", #<Parser::Source::Range example.rb 9...12>]],
[:tSTRING_DEND, ["}", #<Parser::Source::Range example.rb 12...13>]],
[:tSTRING_END, ["\"", #<Parser::Source::Range example.rb 13...14>]], [:tNL, [nil, #<Parser::Source::Range example.rb 14...15>]]]]
```

https://github.com/ruby/prism/commit/c1652a9ee7