SERVER-99351 introduced a new API for the FCV-gated feature flags that checks them against the operation FCV, however, existing feature flag checks were allowed to keep using the old API to ease the transition.

This ticket is for converting all FCV-gated feature flags listed in src/mongo/db/query/query_feature_flags.idl and not listed in SERVER-101566 to use the new API.

The following FCV-gated feature flags should not be converted to the new API:

• Those such that version≤8.0 and default=true, as those are always enabled under any circumstances in MongoDB 8.1+.
• Those that are deprecated or deprecation candidates, such as potentially those listed in fully_disabled_feature_flags.yml.

If some of the feature flags under consideration in this ticket requires non-mechanical work to adapt to the new API, it may be split from this ticket into a new one.