chore(deps): update dependency gts to v2.0.0 (#308)

Author: renovate-bot

packages/google-cloud-asset/package.json

@@ -52,7 +52,7 @@
     "@types/sinon": "^9.0.0",
     "c8": "^7.1.0",
     "codecov": "^3.6.5",
-    "gts": "2.0.0-alpha.9",
+    "gts": "2.0.0",
     "jsdoc": "^3.6.3",
     "jsdoc-fresh": "^1.0.2",
     "jsdoc-region-tag": "^1.0.4",