Auto merge of #5448 - Emerentius:update_new_ret_no_self_docs, r=phansch

Update documentation for new_ret_no_self

changelog: Update documentation for lint new_ret_no_self to reflect that the return type must only contain `Self`, not be `Self`

The lint was changed to be more lenient than the documentation implies in PR #3338 (Related issue #3313)

diff --cc clippy_lints/src/methods/mod.rs
Simple merge