Fix: pass document chat queries as a QuerySet instead of a materialized list (#13638)

In tracemalloc based profiling, not materializing the whole Document list
reduced memory to approximately 20% of the baseline, with a peak memory
that scaled with the library size.  Now, the lazt queryset is used and only
the needed pk value is actually contributing to memory

src/documents/views.py

@@ -2267,7 +2267,7 @@ class ChatStreamingView(GenericAPIView[Any]):
             if not has_perms_owner_aware(request.user, "view_document", document):
                 return HttpResponseForbidden("Insufficient permissions")
 
-            documents = [document]
+            documents = Document.objects.filter(pk=document.pk)
         else:
             documents = Document.objects.filter(
                 id__in=permitted_document_ids(request.user),