do only persist credentials if needed

.github/workflows/update.yml.disabled

@@ -10,6 +10,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # pin@v4.2.2
+        with:
+          persist-credentials: false
       - name: Setup
         run: pip install --require-hashes -r requirements-dev.txt
       - name: Update requirements.txt