Rollup merge of #115566 - zirconium-n:issue-107250-clean-up-unused-to-predicate, r=oli-obk

clean up unneeded `ToPredicate` impls

Part of #107250.
Removed all totally unused impls. And inlined two impls not need to satisify trait bound.

r? `@oli-obk`

Author: GuillaumeGomez