Log Message:
unicode-emoji: update to 13.1.

Note the following two unicode-emoji files:
 emoji-data.txt
 emoji-variation-sequences.txt
have been moved from emoji dir (included in unicode-emoji package):
 https://unicode.org/Public/emoji/${EMOJI_VERSION}/
to ucd dir (included in unicode-character-database package):
 https://unicode.org/Public/${UCD_VERSION}/ucd/emoji/

Upstream changes:

13.1:
 https://home.unicode.org/emoji-13-1-now-final-to-be-widely-available-in-2021/
 https://unicode.org/emoji/charts-13.1/emoji-released.html

 Emoji 13.1 is now final with 217 new emoji sequences!

13.0:
 https://home.unicode.org/announcing-the-unicode-standard-version-13-0/
 https://unicode.org/emoji/charts-13.0/emoji-released.html

 55 emoji characters, including several new emoji for smileys,
 gender neutral people, animals, and the potted plant.