chore(deps): update dependency google-cloud-containeranalysis to v2.6.3 (#230)

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: renovate-bot

container_registry/container_analysis/snippets/requirements.txt

@@ -1,5 +1,5 @@
 google-cloud-pubsub==2.9.0
-google-cloud-containeranalysis==2.6.2
+google-cloud-containeranalysis==2.6.3
 grafeas==1.4.1
 pytest==6.2.5
 flaky==3.7.0