**Reason**
This extension has already been archived on MediaWiki.org, as identified in {T190671}.
The extension page (before archiving) lists a bunch of MediaWiki versions the extension supposedly works with, but that doesn't instill confidence. The latest mentioned version is 1.27, which is mentioned not to work with the supported back-ends.
It appears to have been worked on last in {rEPEX928eca2e31192c3347742b54a453b78098c8e23f}, 6 years ago.
**To-do list**
- This task
-- [ ] Add maintainers of that extension as subscribers to this task
--- Notified Cneubauer on https://www.mediawiki.org/wiki/User_talk:Cneubauer, as they don't have a phabricator account.
-- [X] Archive documentation on `mediawiki.org` (https://www.mediawiki.org/wiki/Extension:Pdf_Export)
-- [X] Archive Wikidata item associated with documentation page (https://www.wikidata.org/wiki/Q21678004)
- Translatewiki.net/translations
-- [ ] Remove from `translatewiki.net` (`groups/MediaWiki/mediawiki-extensions.txt`).
- 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`).
- Repositories
-- [x] Empty repository and add an ARCHIVED file.
-- [x] Archive the extension's diffusion repository: ({rEPEX}).
-- [x] Mark the repository read-only in Gerrit: (https://gerrit.wikimedia.org/r/admin/projects/mediawiki/extensions/PdfExport).
-- [ ] Delete the GitHub mirror: (https://github.com/wikimedia/mediawiki-extensions-PdfExport).