Merge pull request #936 from plugwise/renovate/asottile-pyupgrade-3.x

Update pre-commit hook asottile/pyupgrade to v3.21.0

Author: bouwew

.pre-commit-config.yaml

@@ -21,7 +21,7 @@ repos:
         args:
           - --branch=main
   - repo: https://github.com/asottile/pyupgrade
-    rev: v3.20.0
+    rev: v3.21.0
     hooks:
       - id: pyupgrade
         name: "Checking pyupgrade"