pre-commit-hooks v6.0.0

Fixes

• check-shebang-scripts-are-executable: improve error message.
  • #1115 PR by @homebysix.

Migrating

• now requires python >= 3.9.
  • #1098 PR by @asottile.
• file-contents-sorter: disallow --unique and --ignore-case at the same
  time.
  • #1095 PR by @nemacysts.
  • #794 issue by @teksturi.
• Removed check-byte-order-marker and fix-encoding-pragma.
  • check-byte-order-marker: migrate to fix-byte-order-marker.
  • fix-encoding-pragma: migrate to pyupgrade.
  • #1034 PR by @mxr.
  • #1032 issue by @mxr.
  • #522 PR by @jgowdy.