feat: update python requirements on schedule

.github/workflows/cron-bump-requirements.yml

@@ -0,0 +1,41 @@
+name: Bump python requirements
+on:
+  schedule:
+    - cron: '30 5 15 * *' # 15th of every month, 05:30
+  push:
+    branches:
+      - 'feat/cron-bump-python-requirements'
+
+jobs:
+  create-pull-request:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        # action runners have bazelisk: https://github.com/bazelbuild/bazel/issues/11062
+      - run: mkdir -p "${TEST_TMPDIR}"
+      - name: Mount bazel cache  # Optional
+        uses: actions/cache@v3
+        with:
+          # needs to be an absolute path, not a variable; I've made it match TEST_TMPDIR above
+          path: /tmp/bazel
+          key: _bazel_runner
+      - name: Update requirements
+        # https://stackoverflow.com/questions/68057744/create-pull-request-with-github-action
+        run: |
+            bazel run //lib/python:requirements.update
+            bazel run //lib/python:vendor_requirements
+      - name: Create Pull Request
+        permissions:
+          - contents: write
+          - pull-requests: write
+        uses: peter-evans/[email protected]
+        with:
+          add-paths: lib/python/*
+          token: ${{ secrets.GITHUB_TOKEN }}
+          commit-message: 'chore: bump python requirements'
+          title: 'Bump Python Requirements'
+          body: >
+            This PR is auto-generated by 
+            [create-pull-request](https://github.com/peter-evans/create-pull-request).
+          labels: dependencies
+          branch: chore/bump-python-requirements