Check sync status in DistGitMRHandler

[jpopelka]

We should amend the PackitAPI.sync_release() which we call in DistGitMRHandler to pass check_sync_status=True to PackitAPI.update_dist_git().
The argument was added in packit/packit#1534 and defaults to False because the method is used also by non-source-git-related workflow.

Prior to calling update_dist_git() the sync_release() updates the dist-git repo which makes the later update_dist_git(check_sync_status=True) call fail saying that there are no commits with trailers.

Note: This would be mostly a change in packit but utilized mostly in hardly, that's why it's tracked here.