fix(deps): update dependency @google-cloud/text-to-speech to v4 (#797)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [@google-cloud/text-to-speech](https://togithub.com/googleapis/nodejs-text-to-speech) | [`^3.0.0` -> `^4.0.0`](https://renovatebot.com/diffs/npm/@google-cloud%2ftext-to-speech/3.4.0/4.0.0) | [![age](https://badges.renovateapi.com/packages/npm/@google-cloud%2ftext-to-speech/4.0.0/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/npm/@google-cloud%2ftext-to-speech/4.0.0/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/npm/@google-cloud%2ftext-to-speech/4.0.0/compatibility-slim/3.4.0)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/npm/@google-cloud%2ftext-to-speech/4.0.0/confidence-slim/3.4.0)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/nodejs-text-to-speech</summary>

### [`v4.0.0`](https://togithub.com/googleapis/nodejs-text-to-speech/blob/HEAD/CHANGELOG.md#&#8203;400-httpsgithubcomgoogleapisnodejs-text-to-speechcomparev340v400-2022-06-10)

[Compare Source](https://togithub.com/googleapis/nodejs-text-to-speech/compare/v3.4.0...v4.0.0)

##### ⚠ BREAKING CHANGES

-   update library to use Node 12 ([#&#8203;604](https://togithub.com/googleapis/nodejs-text-to-speech/issues/604))

##### Features

-   Consolidate task details into service API and add orchestration result details ([74f7cfb](https://togithub.com/googleapis/nodejs-text-to-speech/commit/74f7cfb6947c0b9b35dcddb9ede343877b4938a6))
-   promote CustomVoiceParams to v1 ([#&#8203;591](https://togithub.com/googleapis/nodejs-text-to-speech/issues/591)) ([fe647dc](https://togithub.com/googleapis/nodejs-text-to-speech/commit/fe647dc8735792333e0203844279da6ada898e1a))

##### Build System

-   update library to use Node 12 ([#&#8203;604](https://togithub.com/googleapis/nodejs-text-to-speech/issues/604)) ([4395d56](https://togithub.com/googleapis/nodejs-text-to-speech/commit/4395d5696205c257498d33693e53135da998ed38))

</details>

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samples/package.json

@@ -15,7 +15,7 @@
   },
   "dependencies": {
     "@google-cloud/automl": "^3.0.0",
-    "@google-cloud/text-to-speech": "^3.0.0",
+    "@google-cloud/text-to-speech": "^4.0.0",
     "@google-cloud/translate": "^7.0.0",
     "@google-cloud/vision": "^2.0.0",
     "yargs": "^16.0.0"