T295616 sets up a new user preference search-special-page for the default search page on a wiki
When that is live we need to
- set the search-special-page preference to 'MediaSearch' by default on commons
- avoid setting preferences on GET in production.
- migrate the 'sdms-specialsearch-default' preference on commons:
- if it's true for a user, then that user should have their search-special-page preference set to 'Search'
- update the preference code in the MediaSearch extension so that it edits the new preference
- remove the code from MediaSearchHooks.php that sets the search page title in the skin
- Once that's done and merged, the method setSearchPageTitle() can be hard deprecated in Skin.php in core. https://gerrit.wikimedia.org/r/c/mediawiki/core/+/745339