[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/pre-commit/mirrors-mypy: v0.971 → v0.981](pre-commit/mirrors-mypy@v0.971...v0.981)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -22,7 +22,7 @@ repos:
     -   id: pyupgrade
         args: [--py36-plus]
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.971
+    rev: v0.981
     hooks:
     -   id: mypy
         exclude: ^(docs/|tests/)