Outstanding, as of 2021-01-11:
[x] AtEase
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[x] New version used in MediaWiki library dependencies: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/at-ease?branch=master
[ ] Release of said library bumps
[ ] MediaWiki switched to use said library releases
[ ] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/at-ease?branch=master
[x] mediawiki/libs/alea
[x] Already passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] mediawiki/libs/Equivset
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[x] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/equivset?branch=master
[x] mediawiki/libs/HtmlFormatter
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[x] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/html-formatter?branch=master
[x] mediawiki/libs/RemexHtml
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[x] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/remex-html?branch=master
[x] mediawiki/libs/Shellbox
[x] Already passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] mediawiki/libs/XMPReader
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[x] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/xmp-reader?branch=master
[ ] mediawiki/libs/Zest
[x] Passes tests on PHP 8.0
[x] CI runs PHP 8.0 as voting
[x] New version released
[ ] New version used in MediaWiki: https://libraryupgrader2.wmcloud.org/library/composer/wikimedia/zest-css?branch=master