chore(deps): update dependency google-cloud-pubsub to v1.5.0 [(#3781)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/3781)
chore(deps): update dependency google-cloud-pubsub to v1.5.0 [(#3781)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/3781)

Co-authored-by: Bu Sun Kim <e20aa14702d7e04a52a901b5515eeecef97a5b5f@users.noreply.github.com>
googleapis/python-containeranalysis,googleapis/python-containeranalysis