Add django 4 support and bump django in requirements-server

It also enables to remove the version restriction on psycopg2.

Related to swh/infra/sysadm-environment#4772

requirements-server.txt

-django >= 2, < 4
+django
 djangorestframework
-psycopg2 < 2.9
+psycopg2
 setuptools
 xmlschema

swh/deposit/api/private/urls.py

-# Copyright (C) 2017-2022  The Software Heritage developers
+# Copyright (C) 2017-2023  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from django.conf.urls import url
+from django.urls import re_path as url
 
 from ...config import (
     PRIVATE_CHECK_DEPOSIT,

swh/deposit/api/urls.py

-# Copyright (C) 2017-2021  The Software Heritage developers
+# Copyright (C) 2017-2023  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -7,8 +7,8 @@
 
 """
 
-from django.conf.urls import url
 from django.shortcuts import render
+from django.urls import re_path as url
 
 from ..config import COL_IRI, CONT_FILE_IRI, EDIT_IRI, EM_IRI, SD_IRI, SE_IRI, STATE_IRI
 from .collection import CollectionAPI

swh/deposit/urls.py

-# Copyright (C) 2017-2021  The Software Heritage developers
+# Copyright (C) 2017-2023  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -10,8 +10,9 @@ from __future__ import annotations
 
 from typing import Sequence, Union
 
-from django.conf.urls import include, url
+from django.conf.urls import include
 from django.shortcuts import render
+from django.urls import re_path as url
 from django.views.generic.base import RedirectView
 from rest_framework.urlpatterns import format_suffix_patterns