auth/utils: Fix circular import triggered by sphinx autodoc
auth/utils: Fix circular import triggered by sphinx autodoc

Fix "cannot import name 'ADD_FORGE_MODERATOR_PERMISSION' from
'swh.web.auth.utils'" when autodoc processes the admin_views
module from swh.web.add_forge_now.

SoftwareHeritage/swh-web-ui,SoftwareHeritage/swh-web-ui,SoftwareHeritage/swh-web-ui