chore: release 3.1.2 (#464)

Co-authored-by: release-please[bot] <55107282+release-please[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": "^3.1.1",
+    "@google-cloud/text-to-speech": "^3.1.2",
     "yargs": "^16.0.0"
   },
   "devDependencies": {