chore(deps): update dependency backoff to v2.2.1 (#489)

Author: renovate-bot

dataproc/snippets/requirements.txt

@@ -1,5 +1,5 @@
 
-backoff==2.1.2
+backoff==2.2.1
 grpcio==1.49.1
 google-auth==2.12.0
 google-auth-httplib2==0.1.0