chore(deps): update dependency google/cloud-pubsub to v2 (#2003)

Author: renovate-bot

storage/composer.json

@@ -4,7 +4,7 @@
         "paragonie/random_compat": "^9.0.0"
     },
     "require-dev": {
-        "google/cloud-pubsub": "^1.31",
+        "google/cloud-pubsub": "^2.0",
         "guzzlehttp/guzzle": "^7.0"
     }
 }