chore: use 2x faster black mirror (#42)

Committed via https://github.com/asottile/all-repos

Author: henryiii

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
     - id: ruff
       args: [--config=ruff.toml, --fix, --show-fixes]
 
-- repo: https://github.com/psf/black
+- repo: https://github.com/psf/black-pre-commit-mirror
   rev: "23.3.0"
   hooks:
     - id: black