Add supported python versions in the setup.py

Author: bgoujaud

README.md

@@ -4,6 +4,7 @@
 [![Codecov Status](https://codecov.io/gh/PerformanceEstimation/PEPit/branch/master/graph/badge.svg?token=NwT4oACGS4)](https://codecov.io/gh/PerformanceEstimation/PEPit)
 [![Documentation Status](https://readthedocs.org/projects/pepit/badge/?version=latest)](https://pepit.readthedocs.io/en/latest/?badge=latest)
 [![PyPI version](https://badge.fury.io/py/PEPit.svg)](https://pypi.python.org/pypi/PEPit/)
+[![versions](https://img.shields.io/pypi/pyversions/pepit.svg)](https://github.com/pepit/pepit)
 [![Downloads](https://static.pepy.tech/badge/pepit)](https://pepy.tech/project/pepit)
 [![License](https://img.shields.io/github/license/PerformanceEstimation/PEPit.svg)](https://github.com/PerformanceEstimation/PEPit/blob/master/LICENSE)
 

setup.py

@@ -22,6 +22,11 @@
     download_url="https://github.com/PerformanceEstimation/PEPit/archive/refs/tags/{}.tar.gz".format(version),
     classifiers=[
         "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     ],