chore(deps): update dependency grpcio to v1.39.0 (#231)

Author: renovate-bot

dataproc/snippets/requirements.txt

@@ -1,6 +1,6 @@
 
 backoff==1.11.1
-grpcio==1.38.1
+grpcio==1.39.0
 google-auth==1.33.1
 google-auth-httplib2==0.1.0
 google-cloud==0.34.0