CI: add bot to update lockfile on dependabot PRs

.github/workflows/update-lockfile-bot.yml

@@ -0,0 +1,39 @@
+name: Update Lockfile Bot
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - 'dependabot/**'
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  lock:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v3
+        with:
+          enable-cache: true
+          cache-dependency-glob: "uv.lock"
+
+      - name: Set up Python
+        run: uv python install 3.12
+
+      - name: Update lockfile
+        run: |
+          echo "\`\`\`" > uv_output.md
+          XDSL_VERSION_OVERRIDE="0+dynamic" make venv &>> uv_output.md
+          echo "\`\`\`" >> uv_output.md
+      - name: Commit changes
+        run: |
+          git config --global user.name 'github-actions[bot]'
+          git config --global user.email 'github-actions[bot]@users.noreply.github.com'
+          git add uv.lock
+          git commit -m "Update uv lockfile" -F uv_output.md || echo "No changes to commit"
+          git push