add playwright grouping back

Author: Briseus

.github/renovate.json

@@ -63,6 +63,13 @@
       ],
       "groupName": "Node.js"
     },
+    {
+      "matchPackageNames": [
+        "@playwright/test",
+        "mcr.microsoft.com/playwright"
+      ],
+      "groupName": "Playwright"
+    },
     {
       "matchManagers": [
         "dockerfile"