Add workflow to update the formula daily

.github/workflows/update.yml

@@ -0,0 +1,30 @@
+name: Update
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+  schedule:
+    # "At 00:00." / https://crontab.guru/#0_0_*_*_*
+    - cron: '0 0 * * *'
+
+jobs:
+  update:
+    name: Update formula
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v3
+
+      - name: Update formula
+        continue-on-error: true # This step fails when formula is up-to-date
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          git checkout -b update_formula
+          ./scripts/update_formula.sh
+          git add .
+          git commit -m "Update formula"
+          git push origin update_formula
+          gh pr create --title "Update formula" --body "Update formula"