chore(deps): update dependency google-cloud-pubsub to v1.6.1 [(#4242)](GoogleCloudPlatform/python-docs-samples#4242)

Co-authored-by: gcf-merge-on-green[bot] <60162190+gcf-merge-on-green[bot]@users.noreply.github.com>

Author: renovate-bot

samples/api-client/manager/requirements.txt

@@ -4,6 +4,6 @@ google-api-python-client==1.9.3
 google-auth-httplib2==0.0.3
 google-auth==1.18.0
 google-cloud-iot==1.0.0
-google-cloud-pubsub==1.6.0
+google-cloud-pubsub==1.6.1
 paho-mqtt==1.5.0
 pyjwt==1.7.1