chore(deps): update dependency google-cloud-texttospeech to v2.1.0 (#4147)

Author: renovate-bot

translate/cloud-client/hybrid_glossaries/requirements.txt

@@ -1,3 +1,3 @@
 google-cloud-translate==2.0.1
 google-cloud-vision==1.0.0
-google-cloud-texttospeech==2.0.0
+google-cloud-texttospeech==2.1.0