[compiler] Feature flag cleanup (#35825)

Cleans up feature flags that do not have an active experiment and which
we don't currently plan to ship, one commit per flag. Notable removals:
* Automatic (inferred) effect dependencies / Fire: abandoned due to
early feedback. Shipped useEffectEvent which addresses some of the
use-cases.
* Inline JSX transform (experimented, not a consistent win)
* Context selectors (experimented, not a sufficient/consistent win given
the benefit the compiler already provides)
* Instruction Reordering (will try a different approach)

To decide which features to remove, I looked at Meta's internal repos as
well as eslint-pugin-react-hooks to see which flags were never
overridden anywhere. That gave a longer list of flags, from which I then
removed some features that I know are used in OSS.