Fixed stray comment introduced by d3b71b9.

Thanks Claude Paroz for the report.
Fixed #22350 -- Consistently serialize bytes and text in migrations.

Thanks to @treyhunner and Loïc for their suggestions and review.
Fixed #22398 -- Added detail about callable in KEY_FUNCTION docs
Merge pull request #2541 from arachnegl/22398_KEY_FUNCTION_doc_detail

Fixed #22398 -- Added detail about callable in KEY_FUNCTION docs