Merge pull request #472 from pre-commit/pre-commit-ci-update-config

[pre-commit.ci] pre-commit autoupdate

Author: asottile

.pre-commit-config.yaml

@@ -39,7 +39,7 @@ repos:
     hooks:
     -   id: mypy
 -   repo: https://github.com/pre-commit/mirrors-eslint
-    rev: v7.20.0
+    rev: v7.21.0
     hooks:
     -   id: eslint
         args: [--fix]