chore: Add maintenance workflows

Author: jgraichen

.github/workflows/maintenance-cache-wipe.yml

@@ -0,0 +1,13 @@
+---
+name: maintenance-cache-clear
+on:
+  schedule:
+    - cron: "0 0 1 * *"
+  workflow_dispatch:
+
+jobs:
+  cache-clear:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: easimon/wipe-cache@v2

.github/workflows/maintenance-workflow-cleanup.yml

@@ -0,0 +1,17 @@
+---
+name: maintenance-workflow-cleanup
+on:
+  schedule:
+    - cron: "0 0 1 * *"
+  workflow_dispatch:
+
+jobs:
+  delete-workflow-runs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: Mattraks/delete-workflow-runs@v2
+        with:
+          token: ${{ github.token }}
+          repository: ${{ github.repository }}
+          retain_days: 180
+          keep_minimum_runs: 50