chore(deps): update dependency @types/async to v3 (#737)

Author: renovate[bot]

package.json

@@ -73,7 +73,7 @@
   },
   "devDependencies": {
     "@google-cloud/pubsub": "^0.29.0",
-    "@types/async": "^2.0.49",
+    "@types/async": "^3.0.0",
     "@types/compressible": "^2.0.0",
     "@types/concat-stream": "^1.6.0",
     "@types/configstore": "^4.0.0",