The image as built right now does not include any php-related file; however, the docroots link to files in the /srv/mediawiki/php directory:
www-data@mediawiki-pinkunicorn-b5db99bf9-fp27f:/srv/mediawiki/docroot/wikimediafoundation.org/static/current$ ls -lart total 0 lrwxrwxrwx 1 somebody somebody 24 Feb 23 23:42 skins -> /srv/mediawiki/php/skins lrwxrwxrwx 1 somebody somebody 28 Feb 23 23:42 resources -> /srv/mediawiki/php/resources lrwxrwxrwx 1 somebody somebody 29 Feb 23 23:42 extensions -> /srv/mediawiki/php/extensions
and those links are broken within the image. We need to add them back somehow.
Outstanding problematic URLs:
https://en.wikipedia.org/favicon.ico (due to T288848)