Specify in setup.py that setuptools>=40.8.0 is a required dependency (#5293)

Closes #5090

vancoykendall is right that the dependency is used not only during build.
However, for now I added it to `setup.py`, since the migration of
dependencies to `pyproject.toml` has not yet occurred.

Signed-off-by: Anatoly Myachev <[email protected]>

Author: anmyachev

python/setup.py

@@ -711,6 +711,7 @@ def get_git_commit_hash(length=8):
     author_email="[email protected]",
     description="A language and compiler for custom Deep Learning operations",
     long_description="",
+    install_requires=["setuptools>=40.8.0"],
     packages=get_packages(),
     entry_points=get_entry_points(),
     package_data=package_data,