[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/adamchainz/django-upgrade: 1.19.0 → 1.20.0](adamchainz/django-upgrade@1.19.0...1.20.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -21,7 +21,7 @@ repos:
           - id: pyupgrade
             args: [--py38-plus]
     - repo: https://github.com/adamchainz/django-upgrade
-      rev: "1.19.0"
+      rev: "1.20.0"
       hooks:
           - id: django-upgrade
             args: [--target-version, "4.2"]