chore(deps): update dependency @google-cloud/storage to v6 (#948)

Author: renovate-bot

package.json

@@ -51,7 +51,7 @@
     "stream-events": "^1.0.5"
   },
   "devDependencies": {
-    "@google-cloud/storage": "^5.3.0",
+    "@google-cloud/storage": "^6.0.0",
     "@types/extend": "^3.0.1",
     "@types/is": "0.0.21",
     "@types/js-yaml": "^4.0.0",