Don't error log when getting group push rules gives 404 Not Found
...as this happens when no push rules are set for the group and the current behavior causes lots of erratic error messages.
Fixup to 82de3e84 / Add push rule support to group resource (!1730 - merged).
Related issue: https://github.com/pulumi/pulumi-gitlab/issues/514
Edited by Christoffer Sawicki