Remove the Django admin UI

[jeremystretch]

Proposed Changes

Disable the Django admin UI entirely. The few functions it still performs currently will be migrated to dedicated views within the primary UI.

Justification

All aspects of NetBox should be accessible via its primary user interface. Disabling the standalone Django admin UI will allow us to deliver a single, cohesive interface, while eliminating dependencies on django.contrib.admin.

Impact

The following admin views will be migrated to the primary UI (some have already been moved):

• Users
• Groups
• Config revisions
• Permissions
• Tokens
• Background tasks
• Installed plugins

The following admin views will be removed entirely:

• Views registered by python-social-auth
• Any admin views registered by plugins

[abhi1693]

It's not a concern but https://github.com/Onemind-Services-LLC/netbox-secrets/ will need to redesign the UIs to allow for this change. Currently, an admin activates the user key from the admin panel and this list of keys is also only visible on the admin side as the UserKey model does not inherit most of the common functionality of NetBox. Atleast for this plugin, apart from moving the UI to tabler it'll basically be a complete UI overhaul along with the core

[jeremystretch]

Blocked by #14728, #14729

[peteeckel]

No problem here - admin functionality was removed from netbox-plugin-dns a while ago.

[jeremystretch]

After further discussion, we've decided to stop short of completely eliminating support for the Django admin UI. Instead, we'll disable it by default and provide a configuration parameter to enable it, to support any plugins which still require it.

The admin UI will likely be fully removed in a future release.