chore(deps): update dependency google-cloud-pubsub to v2.8.0 (#40)

Author: renovate-bot

packages/google-cloud-contact-center-insights/samples/snippets/requirements-test.txt

@@ -1,4 +1,4 @@
 google-auth==2.0.2
-google-cloud-pubsub==2.7.1
+google-cloud-pubsub==2.8.0
 protobuf==3.17.3
 pytest==6.2.5