Auto merge of #8561 - FoseFx:use_unwrap_or, r=xFrednet

add `or_then_unwrap`

Closes #8557

changelog: New lint [`or_then_unwrap`]

diff --cc CHANGELOG.md
Simple merge

diff --cc clippy_lints/src/lib.register_all.rs
Simple merge

diff --cc clippy_lints/src/lib.register_lints.rs
Simple merge

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