Log out via POST

[chris34]

Even if we dont use django's logout views, we should change to logout via POST (no problem with CSRF)

from https://docs.djangoproject.com/en/4.2/releases/4.1/#log-out-via-get:

Logging out via GET requests to the built-in logout view is deprecated. Use POST requests instead.

If you want to retain the user experience of an HTML link, you can use a form that is styled to appear as a link:

<form id="logout-form" method="post" action="{% url 'admin:logout' %}">
  {% csrf_token %}
  <button type="submit">{% translate "Log out" %}</button>
</form>
#logout-form {
  display: inline;
}
#logout-form button {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  text-decoration: underline;
}