[4.0.x] Fixed #33132 -- Fixed test client handling of querystring only redirects.

Regression in 1e5aa8e1c7.

Backport of b1bf8c8a4b from main

tests/test_client/views.py

@@ -85,6 +85,21 @@ def post_view(request):
     return HttpResponse(t.render(c))
 
 
+def post_then_get_view(request):
+    """
+    A view that expects a POST request, returns a redirect response
+    to itself providing only a ?success=true querystring,
+    the value of this querystring is then rendered upon GET.
+    """
+    if request.method == 'POST':
+        return HttpResponseRedirect('?success=true')
+
+    t = Template('The value of success is {{ value }}.', name='GET Template')
+    c = Context({'value': request.GET.get('success', 'false')})
+
+    return HttpResponse(t.render(c))
+
+
 def json_view(request):
     """
     A view that expects a request with the header 'application/json' and JSON