chore: Create group config for upper bounds file

Author: lqiu96

renovate.json

@@ -88,6 +88,15 @@
     }
   ],
   "packageRules": [
+    {
+      "matchManagers": [
+        "regex"
+      ],
+      "fileMatch": ["/^dependencies\\.txt$/"],
+      "matchDatasources": ["maven"],
+      "groupName": "Upper Bound Dependencies File",
+      "description": "Group all dependencies from the Upper Bound Dependencies File"
+    },
     {
       "matchPackageNames": [
         "com.google.cloud:google-cloud-shared-config"