Description of problem:
"Attach existing sysprep" should not try to get resource at cluster scope when logged in with regular user, it should try to get resource from current project or projects he owned.

Version-Release number of selected component (if applicable):
v4.12.0

How reproducible:

Steps to Reproduce:
1. login with regular user, like "test"
2. create vm from catalog and move to vm scripts tab
3. try to attach existing sysprep

Actual results:
An error is showing ```configmaps is forbidden: User "test" cannot list resource "configmaps" in API group "" at the cluster scope```

Expected results:
It loads configmaps from current project or the projects he can list resources.

Additional info:
Similar bug: https://bugzilla.redhat.com/show_bug.cgi?id=2168859