The Wikimedia wiki farm has a static list of active sites, consumers of this list will be reading from but never writing to this list. Convert all usages of getSiteStore to use getSiteLookup instead.
- Extension:CampaignEvents -> test only, can replace with a mock
- Extension:CentralAuth -> test only, can replace with a mock
- Extension:GlobalBlocking -> test only, can replace with a mock
- Extension:GrowthExperiments -> looks up the language code for a given project ID
- Extension:Wikibase -> already using the restricted SiteLookup sub-interface, the service call can be adjusted safely
- Deprecate MediaWikiServices::getSiteStore
- Maintenance scripts adjusting the sites table -> these will become unnecessary *(won't do on this task)
To follow up in separate work: the core class TestSites seems to be unused now.