Django 5.2 makes the built-in logout view POST-only, which causes
Horizon's GET-based Sign Out link to return HTTP 405.
Convert the user-menu logout to a CSRF-protected POST and
enforce POST in the logout view while preserving WebSSO
redirect logout behavior.
Change-Id: Ieaaf51fab4a4b32d454f8a5d90b304141bd6cf94
Signed-off-by: Owen McGonagle <omcgonag@redhat.com>