fix(deps): update dependency @google-cloud/text-to-speech to v6

Author: renovate-bot

packages/google-cloud-translate/samples/package.json

@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "@google-cloud/automl": "^5.0.0",
-    "@google-cloud/text-to-speech": "^5.0.0",
+    "@google-cloud/text-to-speech": "^6.0.0",
     "@google-cloud/translate": "^9.0.1",
     "@google-cloud/vision": "^5.0.0",
     "yargs": "^17.0.0"