Rollup merge of #144098 - cjgillot:lint-rpitit, r=compiler-errors

Do not lint private-in-public for RPITIT

Fixes the hard error introduced by rust-lang/rust#143357

Instead of trying to accept this hard error directly, this PR copies tests from rust-lang/rust#144020 and removes the error.

If the behaviour is actually desirable, the second commit can be reverted with a proper crater run.

cc rust-lang/rust#143531 for bookkeeping

r? `@compiler-errors`

Author: matthiaskrgr