[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/pre-commit/mirrors-mypy: v0.910-1 → v0.920](pre-commit/mirrors-mypy@v0.910-1...v0.920)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -29,7 +29,7 @@ repos:
         language: python
         additional_dependencies: [pygments, restructuredtext_lint]
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.910-1
+    rev: v0.920
     hooks:
     -   id: mypy
         files: ^(src/|testing/)