tests: remove unused setup.py

tests/fixtures/directory/project_with_transitive_file_dependencies/setup.py

-# -*- coding: utf-8 -*-
-from distutils.core import setup
-
-packages = ["project_with_extras"]
-
-package_data = {"": ["*"]}
-
-extras_require = {"extras_a": ["pendulum>=1.4.4"], "extras_b": ["cachy>=0.2.0"]}
-
-setup_kwargs = {
-    "name": "project-with-extras",
-    "version": "1.2.3",
-    "description": "This is a description",
-    "long_description": None,
-    "author": "Your Name",
-    "author_email": "you@example.com",
-    "url": None,
-    "packages": packages,
-    "package_data": package_data,
-    "extras_require": extras_require,
-}
-
-
-setup(**setup_kwargs)