[pre-commit.ci] pre-commit autoupdate (#740)

updates:
- [github.com/adamchainz/django-upgrade: 1.20.0 → 1.21.0](adamchainz/django-upgrade@1.20.0...1.21.0)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.pre-commit-config.yaml

@@ -52,7 +52,7 @@ repos:
   - id: pyupgrade
     args: ['--keep-mock']
 - repo: https://github.com/adamchainz/django-upgrade
-  rev: '1.20.0'
+  rev: '1.21.0'
   hooks:
   - id: django-upgrade
     args: [--target-version, '4.2']