ci: Add cron action to cleanup old artifacts to avoid hitting GH Actions limits

.github/workflows/clean-old-artifacts.yml

@@ -0,0 +1,24 @@
+name: Remove Old Artifacts
+
+# NOTE - Cleaning artifacts is necessary, storage is limited and the default, not configurable time window is 90 days
+# this is likely too long, so this action will periodically cleanup old artifacts
+# - https://github.com/marketplace/actions/remove-artifacts
+# There is a _lot_ of confusion around the limit for artifacts though - https://github.com/godotengine/godot-proposals/issues/1412#issuecomment-680173450
+# - So likely something we want to bake for a while and see how it goes.
+
+on:
+  schedule:
+    # Every day at 1am
+    - cron: "0 1 * * *"
+
+jobs:
+  remove-old-artifacts:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Remove old artifacts
+        uses: c-hive/gha-remove-artifacts@v1
+        with:
+          age: "1 month"
+          skip-tags: true