mgr/dashboard: disable 'Add Capability' button in rgw user edi… (#32610)

mgr/dashboard: disable 'Add Capability' button in rgw user edit form.

Reviewed-by: Laura Paduano <lpaduano@suse.com>
Reviewed-by: Tiago Melo <tmelo@suse.com>
Reviewed-by: Volker Theile <vtheile@suse.com>

diff --cc src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-user-form/rgw-user-form.component.html
Simple merge