Reason
Community Twitter is unmaintained except for the automated build and translatewiki.net updates. It is also just used on 2 wikis whose versions are < 1.25 and therefore ain't no longer supported nor developed.

To-Do list

• This task
  • Add maintainers of that extension as subscribers to this task (if they have no apparent Phabricator account, notify them on-wiki or via email if possible and note it here).
  • Add Phabricator project <#ProjectX> as a tag for this task, or MediaWiki-extensions-Other if there is no project.
• On-wiki documentation
  • Archive documentation on mediawiki.org (https://www.mediawiki.org/wiki/Extension:Community_Twitter): replace page contents with {{TNT|Archived extension|last revision id before archiving|reason=archive reasons, per [[phab:T######]]}}; include a link to this task in the reason parameter.
  • If documentation page was translatable, remove <translate>, visit Special:PageTranslation, and click "remove from translation" (if you don't have the translation administrator right, ask a user who does).
  • Archive Wikidata item associated with documentation page (https://www.wikidata.org/wiki/Q21676671) (remove nearly all statements, except instance of (P31) = MediaWiki extension (Q6805426), which should add a qualifier end time (P582) = the YYYY-MM-DD date that you decided to archive extension, generally per edit history, change English (and other languages if possible) description to "archived MediaWiki extension" (and its translation)).
• Phabricator
  • Archive Phabricator project <#ProjectX> for the extension.
  • Mark all Phabricator tasks for the extension either Declined or Invalid.
  • Edit Phabricator project <#ProjectX> description for the extension with a link to this ticket.
• Translatewiki.net/translations
  • Remove from translatewiki.net (groups/MediaWiki/mediawiki-extensions.txt) (add translatewiki.net project as a tag for this task).
• Configuration/tests/integrations/etc.
  • Remove from mediawiki/extensions (along with in .gitmodules).
  • Remove tests in [[ https://gerrit.wikimedia.org/g/integration/config | integration/config ]] (zuul/layout.yaml).
  • Remove manifest/other references from mediawiki/vagrant if they exist.
  • Remove from https://doc.wikimedia.org/cover-extensions/ if present (requires Continuous-Integration-Infrastructure shell user to delete directly from the server).
• Repositories
  • Empty repository and add an ARCHIVED file.
  • Archive the diffusion repository for the extension: rECOT extension-CommunityTwitter.
  • Mark the repository read-only in Gerrit.
  • Delete the GitHub mirror.