chore(deps): update dependency gts to v6

Author: renovate-bot

system-test/fixtures/sample/package.json

@@ -18,6 +18,6 @@
   "devDependencies": {
     "@types/node": "^22.0.0",
     "typescript": "^5.1.6",
-    "gts": "^5.0.0"
+    "gts": "^6.0.0"
   }
 }