maintenance-update.yml: Fixes steps order for cache setup

.github/workflows/maintenance-update.yml

@@ -8,11 +8,11 @@ jobs:
   update:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
           python-version: "3.13"
           cache: poetry
-      - uses: actions/checkout@v4
       - run: pipx run poetry update --lock
       - id: commit-and-push
         uses: stefanzweifel/git-auto-commit-action@v5