fix(deps): update dependency protobufjs to v8

Author: renovate-bot

package.json

@@ -68,7 +68,7 @@
     "fast-deep-equal": "^3.1.3",
     "functional-red-black-tree": "^1.0.1",
     "google-gax": "^5.0.1",
-    "protobufjs": "^7.5.3"
+    "protobufjs": "^8.0.0"
   },
   "devDependencies": {
     "@google-cloud/cloud-rad": "^0.4.10",