The emoji data in emoji-variation-sequences.txt was not used for
in test/ruby/enc/test_emoji_breaks.rb, for unknown reasons.
It turned out that the format of each of the emoji data/test files
is slightly different, and that we didn't take into account that
empty fields after a semicolon, as present in
emoji-variation-sequences.txt, led to less fields than expected
when using split.
This addresses issue #18027.