Remove redundant runtime requirement on setuptools

The dependency was dropped in 99a1cf3

Signed-off-by: Miro Hrončok <[email protected]>

Author: hroncok

setup.py

@@ -97,7 +97,7 @@
       # setup also requires libsepol and libselinux
       # C libraries and headers to compile.
       setup_requires=['setuptools', 'Cython>=0.29.14'],
-      install_requires=['setuptools'],
+      install_requires=[],
       extras_require={
           "analysis": ["networkx>=2.6", "pygraphviz"],
           "test": "tox"