Update the bundled Unicode Emoji data to 18.0 #1347

Update the bundled Unicode Emoji data to 18.0

The emoji normalizer from #1313 ships Unicode Emoji 17.0 sequences, the same Unicode version as the other bundled Unicode tables, so 3.0 stays on one version. Emoji 18.0 adds 19 sequences that the 17.0 data does not know, so those emoji pass through the normalizer unchanged.

For 3.1:

• Regenerate EmojiSequences.txt from the Emoji 18.0 release with dev/UnicodeEmojiSequenceGenerator and update the pinned release, SHA-256 values and sequence count in the generator.
• Update the Emoji 17.0 count and oracle in the normalizer test, the version in the Javadoc and manual, and the Unicode copyright year in the runtime NOTICE.
• Check the other bundled Unicode tables for an 18.0 release and move them in the same pass, so the runtime stays on one Unicode version.

Depends on #1313 being merged first. An 18.0 version of the data already exists and was tested while #1313 was reviewed, so this is a data refresh, not new code.