Rollup merge of #83269 - bstrie:revertdep, r=m-ou-se

Rollup merge of #83269 - bstrie:revertdep, r=m-ou-se

Revert the second deprecation of collections::Bound

Per the review at https://github.com/rust-lang/rust/pull/82122#discussion_r596448078 and the decision at https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/unavoidable.20breakage.20when.20deprecating.20an.20enum.3F , revert this small portion of #82122 for the time being. This doesn't affect the other components of that patch, i.e. `intrinsics::drop_in_place` is still deprecated-for-real, and uses of `collections::Bound` remain removed from the repo.