The CloudManager git repository is Adobe's repository, so you need to check with them your use case by submitting a support ticket. But generally, you can use your own GitHub enterprise repository as a "mirror" repository to Adobe's one, that is the recommended approach.
You can read more about that here: https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/implementing/using-...
Esteban Bustamante