[backport v2.10] [SURE-8794] Deploying ClusterGroup from GitRepo results in loop

[rancherbot]

This is a backport issue for #2859, automatically created via GitHub Actions workflow initiated by @p-se

Original issue body:

Deploying a ClusterGroup from a GitRepo which also contains accompanying other GitRepo resources that use those newly created ClusterGroups result in a loop.

This loop triggers ClusterGroups and appends a message to it that endlessly grows, until the limit of etcd is hit. In which case Fleet is supposedly blocked.

The issue can be reproduced by adding this GitRepo resource to the cluster. The issue was reproducible on the latest Fleet development version at the time and did not require a Rancher installation to reproduce. The cluster was prepared using dev/setup-multi-cluster.