chore(deps): update dependency google-cloud-pubsub to v2.9.0 (#649)

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

Author: renovate-bot

samples/snippets/requirements.txt

@@ -1,3 +1,3 @@
-google-cloud-pubsub==2.8.0
+google-cloud-pubsub==2.9.0
 google-cloud-storage==1.42.3
 pandas==1.1.5