[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/psf/black: 21.9b0 → 21.10b0](psf/black@21.9b0...21.10b0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -20,7 +20,7 @@ repos:
     hooks:
       - id: isort
   - repo: https://github.com/psf/black
-    rev: 21.9b0
+    rev: 21.10b0
     hooks:
       - id: black
   - repo: https://github.com/asottile/pyupgrade