Restore the tests command and deprecate access to the module.

Closes #4520; Closes #4519.

newsfragments/4520.feature.rst

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+Restore the tests command and deprecate access to the module. (#4519)

setuptools/command/test.py

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+from setuptools import Command
+from setuptools.warnings import SetuptoolsDeprecationWarning
+
+
+def __getattr__(name):
+    if name == 'test':
+        SetuptoolsDeprecationWarning.emit(
+            "The test command is disabled and references to it are deprecated.",
+            "Please remove any references to `setuptools.command.test` in all "
+            "supported versions of the affected package.",
+            due_date=(2024, 11, 15),
+            stacklevel=2,
+        )
+        return _test
+    raise AttributeError(name)
+
+
+class _test(Command):
+    """
+    Stub to warn when test command is referenced or used.
+    """
+
+    description = "stub for old test command (do not use)"
+
+    user_options = [
+        ('test-module=', 'm', "Run 'test_suite' in specified module"),
+        (
+            'test-suite=',
+            's',
+            "Run single test, case or suite (e.g. 'module.test_suite')",
+        ),
+        ('test-runner=', 'r', "Test runner to use"),
+    ]
+
+    def initialize_options(self):
+        pass
+
+    def finalize_options(self):
+        pass
+
+    def run(self):
+        raise RuntimeError("Support for the test command was removed in Setuptools 72")