Add Github workflow for updating Github Actions.

.github/workflows/update_github_actions.yml

@@ -0,0 +1,48 @@
+---
+name: Update GitHub Actions
+on:
+  schedule:
+    - cron: 0 3 * * 0
+  push:
+jobs:
+  update_github_actions:
+    name: Update GitHub Actions
+    runs-on: ubuntu-latest
+    steps:
+      - name: Look up Git repository in cache
+        uses: actions/cache/restore@v4
+        with:
+          path: .git/
+          key: update-github-actions-cache-git-${{ github.run_id }}
+          restore-keys: |
+            update-github-actions-cache-git
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: bugfix
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version-file: .version-python
+      - name: Generate token
+        uses: actions/create-github-app-token@v1
+        id: app-token
+        with:
+          app-id: ${{ secrets.TOKEN_APP_ID }}
+          private-key: ${{ secrets.TOKEN_APP_SECRET }}
+      - name: Update GitHub Actions
+        run: |
+          GITHUB_TOKEN=${{ steps.app-token.outputs.token }} ./build update_github_actions
+          git add .github/workflows/*.y*ml
+      - name: Check for uncommitted changes
+        id: check-for-changes
+        run: git diff-index --cached --quiet HEAD || echo '::set-output name=has-changes::true'
+      - name: Commit changes
+        if: ${{ steps.check-for-changes.outputs.has-changes == 'true' }}
+        run: git commit -m "[Bot] Update GitHub Actions."
+      - name: Save Git repository to cache
+        uses: actions/cache/save@v4
+        if: success() || failure()
+        with:
+          path: .git/
+          key: update-github-actions-cache-git-${{ github.run_id }}