Keep GitHub workflow alive

GitHub disables workflows if there is no activity in the repository after
60 days. Run a separate standalone job to re-enable the workflow on a
regular scheduled job.

Signed-off-by: Christopher Obbard <[email protected]>

Author: obbardc

.github/workflows/ci.yaml

@@ -320,6 +320,18 @@ jobs:
         with:
           jobs: ${{ toJSON(needs) }}
 
+  # Keep workflow alive
+  # See https://docs.github.com/en/actions/learn-github-actions/usage-limits-billing-and-administration#disabling-and-enabling-workflows
+  workflow-keepalive:
+    if: github.event_name == 'schedule'
+    runs-on: ubuntu-latest
+    needs:
+      - allgreen
+    permissions:
+      actions: write
+    steps:
+      - uses: liskin/[email protected]
+
   publish-github:
     name: Publish to GHCR
     needs: