chore: group Renovate eslint-related updates monthly (#1682)

Author: MikeMcC399

renovate.json

@@ -18,6 +18,14 @@
       "matchDepTypes": ["dependencies"],
       "enabled": false
     },
+    {
+      "matchPackageNames": [
+        "/eslint/",
+        "globals"
+      ],
+      "groupName": "eslint",
+      "extends": ["schedule:monthly"]
+    },
     {
       "matchPackageNames": ["@types/node"],
       "extends": ["schedule:quarterly"]