chore(deps): update dependency gts to v6

Author: renovate-bot

samples/package.json

@@ -41,7 +41,7 @@
     "@google-cloud/typeless-sample-bot": "^3.0.0",
     "@types/chai": "^4.2.16",
     "chai": "^4.2.0",
-    "gts": "^5.0.0",
+    "gts": "^6.0.0",
     "lru-cache": "9.1.2",
     "mocha": "^9.2.2",
     "rimraf": "5.0.9",

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"
   }
 }