* Removes an unneeded `#![warn(clippy::extra_unused_lifetimes)]` from the `needless_lifetimes` test - the tests for those are in a different file. * Renames `unused_lt.{rs,stderr}` to `extra_unused_lifetimes.{rs,stderr}` * Renames `lifetimes.{rs,stderr}` to `needless_lifetimes.{rs,stderr}`