Use Django 4.0.x for now. (#573)

* Use Django 4.0.x for now.

* Use django 4.0.x for now

web/Dockerfile

@@ -18,7 +18,7 @@ RUN --mount=type=cache,target=/root/.cache \
 	&& apk add --no-cache --virtual .mailman-rundeps bash sassc \
 	   postgresql-client mysql-client py3-mysqlclient curl mailcap gettext \
 	   python3 py3-pip xapian-core xapian-bindings-python3 libffi pcre-dev py-cryptography \
-	&& python3 -m pip install -U 'Django<4.2' pip setuptools wheel \
+	&& python3 -m pip install -U 'Django<4.1' pip setuptools wheel \
 	&& pip install -r /tmp/requirements.txt \
 		whoosh \
 		uwsgi \

web/Dockerfile.dev

@@ -37,7 +37,7 @@ RUN --mount=type=cache,target=/root/.cache \
 	tzdata \
         diskcache \
         django-utils-six \
-    && python3 -m pip install -U 'Django<4.2' \
+    && python3 -m pip install -U 'Django<4.1' \
     && python3 -m pip install -U \
        git+https://gitlab.com/mailman/django-mailman3 \
     && apk del .build-deps \