Revert workflows to ubuntu-latest until CI image is seeded.

Co-authored-by: Cursor <[email protected]>

.gitea/workflows/dependency-update-bot.yml

@@ -7,17 +7,22 @@ on:
 
 jobs:
   update-check:
-    runs-on: python-repositories-ci
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
         with:
           token: ${{ secrets.CI_RUNNER_TOKEN }}
 
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version-file: .python-version
+
+      - name: Install uv
+        run: pip install uv
+
       - name: Upgrade dependencies
-        env:
-          UV_INDEX_GITEA_USERNAME: ci-bot
-          UV_INDEX_GITEA_PASSWORD: ${{ secrets.CI_RUNNER_TOKEN }}
         run: uv lock --upgrade
 
       - name: Commit and push changes