fix: upgrade @google-cloud/text-to-speech from 3.2.2 to 3.4.0 (#19)

Snyk has created this PR to upgrade @google-cloud/text-to-speech from 3.2.2 to 3.4.0.

See this package in npm:
https://www.npmjs.com/package/@google-cloud/text-to-speech

See this project in Snyk:
https://app.snyk.io/org/davehorton/project/b7e09765-19b2-4aa5-90ba-10432e250041?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -18,7 +18,7 @@
   },
   "dependencies": {
     "@google-cloud/speech": "^4.9.0",
-    "@google-cloud/text-to-speech": "^3.1.3",
+    "@google-cloud/text-to-speech": "^3.4.0",
     "@jambonz/db-helpers": "^0.6.12",
     "@jambonz/realtimedb-helpers": "^0.4.14",
     "@jambonz/time-series": "^0.1.5",