ci(renovate): Slow down renovate merge requests

renovate.json

@@ -150,6 +150,17 @@
       ],
       "minimumReleaseAge": "14 days"
     },
+    {
+      "matchDatasources": [
+        "helm"
+      ],
+      "matchPackageNames": [
+        "renovate"
+      ],
+      "schedule": [
+        "on Monday"
+      ]
+    },
     {
       "matchFileNames": [
         "images/kos/**"