chore(deps): update dependency google-cloud-video-transcoder to v1.8.0 (#291)

Author: renovate-bot

video/transcoder/requirements.txt

@@ -1,3 +1,3 @@
 google-api-python-client==2.80.0
 grpcio==1.51.3
-google-cloud-video-transcoder==1.7.0
+google-cloud-video-transcoder==1.8.0