Add CI workflow to auto-update pre-commit hooks

Author: alexdewar

.github/workflows/pre-commit-autoupdate.yml

@@ -0,0 +1,25 @@
+name: Pre-commit auto-update
+
+on:
+  schedule:
+    - cron: 0 0 * * 1 # midnight every Monday
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-update:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+      - uses: browniebroke/pre-commit-autoupdate-action@1
+      - uses: peter-evans/create-pull-request@v7
+        with:
+          token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
+          branch: update/pre-commit-hooks
+          title: Update pre-commit hooks
+          commit-message: "chore: update pre-commit hooks"
+          body: Update versions of pre-commit hooks to latest version.