[compiler] Cleanup and enable validateNoVoidUseMemo (#34882)

This is a great validation, so let's enable by default. Changes:
* Move the validation logic into ValidateUseMemo alongside the new check
that the useMemo result is used
* Update the lint description
* Make the void memo errors lint-only, they don't require us to skip
compilation (as evidenced by the fact that we've had this validation
off)

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[//]: # (BEGIN SAPLING FOOTER)
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* #34855
* __->__ #34882

DiffTrain build for [1324e1bb1f867e8b2108ca52a1d4e2d4ef56d2d9](https://github.com/facebook/react/commit/1324e1bb1f867e8b2108ca52a1d4e2d4ef56d2d9)