When creating T257260: entitysources: Clean up any remainders of the legacy back/compat config in the mediawiki-config repository I realized that these config options are still used in various places in code (mainly tests and defaults) which is not ideal.
These should all be removed so that we can safely unset these in production.
All code should be getting these things from entity sources, including tests.
Looking at EntitySourceDefinitionsLegacyRepoSettingsParser this probably is:
And for EntitySourceDefinitionsLegacyClientSettingsParser: