[pre-commit.ci] pre-commit autoupdate (#770)

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

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

.pre-commit-config.yaml

@@ -32,7 +32,7 @@ repos:
       - id: isort
 
   - repo: https://github.com/adamchainz/django-upgrade
-    rev: 1.19.0
+    rev: 1.20.0
     hooks:
       - id: django-upgrade
         args: [--target-version, "3.2"]