chore: Add upper bounds dependencies file to renovate config

Author: lqiu96

renovate.json

@@ -96,6 +96,21 @@
       ],
       "depNameTemplate": "com.google.cloud:sdk-platform-java-config",
       "datasourceTemplate": "maven"
+    },
+    {
+      "matchManagers": [
+        "regex"
+      ],
+      "semanticCommitType": "chore",
+      "matchFileNames": [
+        "dependencies.txt"
+      ],
+      "matchDatasources": [
+        "maven"
+      ],
+      "groupName": "Upper Bound Dependencies File",
+      "description": "Group all dependencies from the Upper Bound Dependencies File",
+      "enabled": true
     }
   ]
 }