Don't update staging from production as often as it's not necessary

We don't need to update so often and this reduces the use of the minutes per
month we have access to free for GitHub actions (2000 at the time of writing).
See https://docs.github.com/en/billing/managing-billing-for-your-products/managing-billing-for-github-actions/about-billing-for-github-actions#included-storage-and-minutes

.github/workflows/backup.yml

@@ -12,15 +12,5 @@ jobs:
     - name: Run backup script
       run: ./infra/backup.sh
       shell: bash
-      env:
-        CLERK_PRIVATE_SSH_KEY: ${{ secrets.CLERK_PRIVATE_SSH_KEY }}
-  update_staging:
-    runs-on: ubuntu-latest
-    needs: backup
-    steps:
-    - uses: actions/checkout@v4
-    - name: Run backup script
-      run: ./infra/staging/database-restore.sh
-      shell: bash
       env:
         CLERK_PRIVATE_SSH_KEY: ${{ secrets.CLERK_PRIVATE_SSH_KEY }}

.github/workflows/staging.yml

@@ -0,0 +1,16 @@
+name: Staging
+on:
+  workflow_dispatch:
+  schedule:
+    # Update staging environment at 0415 AEST (18:15 UTC) each Saturday 
+    - cron: "15 18 * * SAT"
+jobs:
+  update_staging:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Run backup script
+      run: ./infra/staging/database-restore.sh
+      shell: bash
+      env:
+        CLERK_PRIVATE_SSH_KEY: ${{ secrets.CLERK_PRIVATE_SSH_KEY }}