Auto merge of #4392 - phansch:cleanups, r=flip1995

Remove unused dev scripts/files

781794d: Remove util/update_lints.py

 * This has been deprecated for ~10 months, so I think it's fine to remove now.

90a4293: Remove publishing things

 * Clippy is no longer published via crates.io, so these docs and the script
   are not needed anymore.

changelog: none

Author: bors