[channels] Relax django-stubs dependency

Author: hartungstenio

stubs/channels/METADATA.toml

@@ -1,6 +1,6 @@
 version = "4.3.*"
 upstream_repository = "https://github.com/django/channels"
-requires = ["django-stubs>=4.2,<5.3", "asgiref"]
+requires = ["django-stubs>=4.2", "asgiref"]
 
 [tool.stubtest]
 mypy_plugins = ['mypy_django_plugin.main']