chore(deps): update dependency google-cloud-texttospeech to v2.9.1 (#324)

Co-authored-by: Anthonios Partheniou <[email protected]>

Author: 2 people

translation/samples/snippets/hybrid_glossaries/requirements.txt

@@ -1,3 +1,3 @@
 google-cloud-translate==3.6.1
 google-cloud-vision==2.6.3
-google-cloud-texttospeech==2.9.0
+google-cloud-texttospeech==2.9.1