fix: migrate to native namespace packages

setup.py

@@ -16,6 +16,7 @@
 import os
 
 import setuptools
+from setuptools import find_namespace_packages
 
 # Package metadata.
 
@@ -39,12 +40,6 @@
 with io.open(readme_filename, encoding="utf-8") as readme_file:
     readme = readme_file.read()
 
-# Only include packages under the 'google' namespace. Do not include tests,
-# benchmarks, etc.
-packages = [
-    package for package in setuptools.find_packages() if package.startswith("google")
-]
-
 setuptools.setup(
     name=name,
     version=version,
@@ -70,7 +65,7 @@
         "Topic :: Internet",
     ],
     platforms="Posix; MacOS X; Windows",
-    packages=packages,
+    packages=find_namespace_packages(exclude=("tests*", "testing*")),
     install_requires=dependencies,
     python_requires=">=3.7",
     include_package_data=True,