Remove run-time dependency on setuptools (#201)

It was needed for `pkg_resources`-style namespace packages, but that's no longer a problem here.

Author: cjwatson

CHANGES.rst

@@ -5,7 +5,7 @@
 8.1 (unreleased)
 ================
 
-- Nothing changed yet.
+- Remove run-time dependency on ``setuptools``.
 
 
 8.0 (2025-09-12)

setup.py

@@ -24,7 +24,6 @@
 version = '8.1.dev0'
 
 INSTALL_REQUIRES = [
-    'setuptools',
     'zope.exceptions',
     'zope.interface',
 ]

src/zope/testrunner/__init__.py

@@ -17,8 +17,6 @@
 import os
 import sys
 
-import pkg_resources  # noqa: F401 unused import, see GitHub issue #194
-
 
 def run(defaults=None, args=None, script_parts=None, cwd=None, warnings=None):
     """Main runner function which can be and is being used from main programs.