[setup] use find_namespace_packages instead of find_packages

setup.py

@@ -2,7 +2,7 @@
 
 import os
 from setuptools import setup
-from setuptools import find_packages
+from setuptools import find_namespace_packages
 from pathlib import Path
 
 
@@ -39,7 +39,7 @@ setup(
     url="https://github.com/thomst/django-more-admin-filters",
     license="BSD License",
     platforms=["OS Independent"],
-    packages=find_packages(exclude=["tests"]),
+    packages=find_namespace_packages(exclude=["tests"]),
     include_package_data=True,
     install_requires=[
         "Django>=2.2,<5.0",