During the transition period where we have mw-on-k8s as well as bare-metal mediawiki servers, use the container image as the source for /srv/mediawiki on the deploy server.
Note: The container image does not contain /srv/mediawiki/php-<vers>/cache/l10n/upstream/ JSON files since they're not needed when running the container. I hope to avoid having to deal with those files at all anymore by way of T295304: Improve efficiency of scap l10n operations.