drop usage of ugettext (deprecated in django 3.0, removed in 4.0) in favour of gettext

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

apikeys/authentication.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from rest_framework import authentication
 from rest_framework.exceptions import AuthenticationFailed
 

backend/mixins.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.views.generic import TemplateView
 from django.core.exceptions import PermissionDenied
 from django.core import signing

impersonate/views.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.views.generic import View
 from django.shortcuts import redirect
 from django.core.exceptions import PermissionDenied

mia/views.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django import forms
 from django.shortcuts import redirect
 from django.views.generic import TemplateView

minechangelogs/views.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django import http, forms
 from django.views.generic.edit import FormView
 from django.core.exceptions import PermissionDenied

process/mixins.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import get_object_or_404
 from django.urls import reverse

process/views.py

 from __future__ import annotations
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.shortcuts import redirect, get_object_or_404
 from django.views.generic import TemplateView, View
 from django.views.generic.edit import FormView

public/views.py

@@ -2,7 +2,7 @@ from django import http, forms
 from django.shortcuts import redirect
 from django.urls import reverse
 from django.core.exceptions import PermissionDenied
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.utils.timezone import now
 from django.views.generic import View
 from django.views.generic.edit import FormView

signon/providers.py

@@ -58,7 +58,7 @@ class BoundProvider:
         Return a dict describing actions for actions that can be taken for this
         provider in the current request
         """
-        from django.utils.translation import ugettext as _
+        from django.utils.translation import gettext as _
         from django.urls import reverse
         my_user = None
         other_users = set()
@@ -131,7 +131,7 @@ class Provider:
 
 class BoundBaseSessionProvider(BoundProvider):
     def get_actions(self):
-        from django.utils.translation import ugettext as _
+        from django.utils.translation import gettext as _
         from django.urls import reverse
         res = super().get_actions()
         res.append({