[pre-commit.ci] pre-commit autoupdate

updates:
- https://github.com/ambv/black → https://github.com/psf/black-pre-commit-mirror
- [github.com/psf/black-pre-commit-mirror: stable → 26.1.0](psf/black-pre-commit-mirror@stable...26.1.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 fail_fast: true
 repos:
-  - repo: https://github.com/ambv/black
-    rev:  stable
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev:  26.1.0
     hooks:
       - id:               black
         language_version: python3.7