Reason: https://gerrit.wikimedia.org/r/#/admin/projects/mediawiki/extensions/Phalanx is marked as read-only, and the extension page on MediaWiki is marked as unmantained and T70974 indicates that indeed the extension is abandoned.
- Archive documentation on mediawiki.org https://www.mediawiki.org/wiki/Extension:Phalanx
- Empty repo and note archive status
- Remove from mediawiki/extensions (along with in .gitmodules) [was not there]
- Remove tests in integration/config (zuul/layout.yaml) [already done]
- Remove from translatewiki (groups/MediaWiki/mediawiki-extensions.txt )
- Archive the extension's diffusion repository: rEPHA
- Delete the GitHub mirror: https://github.com/wikimedia/mediawiki-extensions-Phalanx (needs someone in #acl*releng)
- Mark gerrit repo as read-only: https://gerrit.wikimedia.org/r/#/admin/projects/mediawiki/extensions/Phalanx