ci: pre-commit autoupdate (#1035)

updates:
- [github.com/adamchainz/django-upgrade: 1.20.0 → 1.21.0](adamchainz/django-upgrade@1.20.0...1.21.0)
- [github.com/astral-sh/ruff-pre-commit: v0.6.3 → v0.6.8](astral-sh/ruff-pre-commit@v0.6.3...v0.6.8)

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

.pre-commit-config.yaml

@@ -14,7 +14,7 @@ fail_fast: true
 
 repos:
   - repo: https://github.com/adamchainz/django-upgrade
-    rev: '1.20.0'
+    rev: '1.21.0'
     hooks:
       - id: django-upgrade
         args: [--target-version, "3.2"]
@@ -24,7 +24,7 @@ repos:
        -  id: pyupgrade
           args: ["--py310-plus"]
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.6.3
+    rev: v0.6.8
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]