chore(deps): update dependency @google-cloud/nodejs-repo-tools to v3 (#447)

Author: renovate[bot]

handwritten/firestore/package.json

@@ -58,7 +58,7 @@
     "through2": "^3.0.0"
   },
   "devDependencies": {
-    "@google-cloud/nodejs-repo-tools": "^2.3.5",
+    "@google-cloud/nodejs-repo-tools": "^3.0.0",
     "@types/assert": "^1.4.0",
     "@types/chai": "^4.1.7",
     "@types/chai-as-promised": "^7.1.0",