chore(renovate): receive next bumps in fixtures (#487)

See
https://linear.app/netlify/issue/FRA-511/spike-investigate-viability-of-configuring-renovate-to-open-prs-for.

Author: serhalp

renovate.json

@@ -1,4 +1,15 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": ["local>netlify/renovate-config"]
+  "extends": ["local>netlify/renovate-config"],
+  "packageRules": [
+    {
+      "description": "Stable & unstable Next.js bumps in test fixtures (no automerge)",
+      "matchFileNames": ["tests/**/fixtures/**/package.json"],
+      "matchPackageNames": ["next"],
+      "ignoreUnstable": false,
+      "labels": ["bump-framework-in-fixtures", "run-e2e-tests'))"],
+      "schedule": null,
+      "automerge": false
+    }
+  ]
 }