Merge branch...

Merge branch '461055-backend-support-for-instance-level-self-managed-model-configuration' into 'master' 

Create Self-Managed model GQL mutation

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/153241



Merged-by: Mohamed Hamda <mhamda@gitlab.com>
Approved-by: Bruno Cardoso <bcardoso@gitlab.com>
Approved-by: Mohamed Hamda <mhamda@gitlab.com>
Reviewed-by: Patrick Cyiza <jpcyiza@gitlab.com>
Reviewed-by: Mohamed Hamda <mhamda@gitlab.com>
Reviewed-by: Julie Huang <julhuang@gitlab.com>
Co-authored-by: Patrick Cyiza <jpcyiza@gitlab.com>
Co-authored-by: Julie Huang <julhuang@gitlab.com>