chore(deps): update dependency gts to v3 (#641)

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: renovate-bot

package.json

@@ -54,7 +54,7 @@
     "@types/sinon": "^10.0.0",
     "c8": "^7.0.0",
     "codecov": "^3.0.2",
-    "gts": "^2.0.0",
+    "gts": "^3.0.0",
     "jsdoc": "^3.5.5",
     "jsdoc-fresh": "^1.0.1",
     "jsdoc-region-tag": "^1.0.2",