Auto merge of #154292 - Zalathar:def-kind, r=petrochenkov

Don't use disk-cache for query `def_kind`

From what I can tell, the `def_kind` query has no local provider, and is always given its value via query feeding, usually from `TyCtxt::create_def`.

If that's the case, there should never be any opportunity for a previous value to be loaded from disk-cache, so serializing the current-session values is a waste of time.