Reason
Unmaintained, and have errors in CI tests, example T206290: ImageMetrics qunit test mw.imageMetrics.LoadingTimeLogger is failing.

To-do list

• This task
  • Add maintainers of that extension/skin 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 <#ImageMetrics> as a tag for this task.
• On-wiki documentation
  • Archive documentation on mediawiki.org (https://www.mediawiki.org/wiki/Extension:ImageMetrics): replace page contents with {{Archived extension|2202514|reason=archive reasons, per {{phab|T240799}}.}}.
  • Update Wikidata item (https://www.wikidata.org/wiki/Special:EntityPage/Q21677294) associated with documentation page
    • add statement Abandonware (Q281039) to instance of (P31) together with qualifier start time (P580) = the YYYY-MM-DD date that you decided to archive extension/skin (generally per edit history)
    • add qualifier end time (P582) = the YYYY-MM-DD (same date as above) to instance of (P31) = MediaWiki extension (Q6805426)/MediaWiki skin (Q21996535)
• Phabricator
  • Mark all Phabricator tasks for the extension/skin either Declined or Invalid.
  • Archive Phabricator project <#ImageMetrics> for the extension/skin.
  • Edit Phabricator project <#ImageMetrics> description for the extension/skin with a link to this ticket.
• Translatewiki.net/translations
  • Remove from translatewiki.net ([[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/groups/MediaWiki/mediawiki-extensions.txt | groups/MediaWiki/mediawiki-extensions.txt ]] / [[ https://gerrit.wikimedia.org/r/plugins/gitiles/translatewiki/+/refs/heads/master/groups/MediaWiki/mediawiki-skins.txt | groups/MediaWiki/mediawiki-skins.txt ]]).
• Configuration/tests/integrations/etc.
  • Remove from [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/+/master | mediawiki/extensions ]] / [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/skins/+/master | mediawiki/skins ]] (along with in [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/+/master/.gitmodules | .gitmodules ]]).
  • Remove tests in [[ https://gerrit.wikimedia.org/g/integration/config | integration/config ]] ([[ https://gerrit.wikimedia.org/r/plugins/gitiles/integration/config/+/master/zuul/layout.yaml | zuul/layout.yaml ]]).
  • Remove manifest/other references from [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/vagrant/+/master | mediawiki/vagrant ]] if they exist.
• Repositories
  • Empty repository, leaving only the README indicating the repo is archived, and referring to this task by URL.
  • Mark the repository read-only in Gerrit (Edit description to prepend "[ARCHIVED]" and append Task reference): (https://gerrit.wikimedia.org/r/#/admin/projects/mediawiki/extensions/ImageMetrics).
  • Archive the diffusion repository for the extension/skin: (rEIME).
  • Archive the GitHub mirror: (https://github.com/wikimedia/mediawiki-extensions-ImageMetrics).