Create gh-workflow-immortality.yml

Added a new GH action in order to prevent the auto-disable from GH when no actions for 60 days are made in the repo 
Rif. https://github.com/marketplace/actions/github-workflow-immortality

.github/workflows/gh-workflow-immortality.yml

@@ -0,0 +1,20 @@
+name: GitHub Workflow Immortality
+
+on:
+  schedule:
+    # run once a month on the first day of the month at 00:20 UTC
+    - cron: '20 0 1 * *'
+  workflow_dispatch: {}
+
+jobs:
+  keepalive:
+    name: GitHub Workflow Immortality
+
+    runs-on: ubuntu-latest
+    permissions: {}
+
+    steps:
+      - name: Keep cronjob based triggers of GitHub workflows alive
+        uses: PhrozenByte/gh-workflow-immortality@v1
+        with:
+          secret: ${{ secrets.GH_WORKFLOW_IMMORTALITY }}