chore(main): release 4.0.3 (#626)

* chore(main): release 4.0.3

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: release-please[bot]

texttospeech/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout=60000"
   },
   "dependencies": {
-    "@google-cloud/text-to-speech": "^4.0.2",
+    "@google-cloud/text-to-speech": "^4.0.3",
     "yargs": "^16.0.0"
   },
   "devDependencies": {