Make it clear that py38 is EOL

Author: ostefano

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = tau-clients
-version = 0.3.2
+version = 0.3.3
 author = Stefano Ortolani
 description = Set of clients to interface with various VMware products
 long_description = file: README.md
@@ -21,7 +21,7 @@ classifiers =
 package_dir =
     = src
 packages = find:
-python_requires = >=3.8
+python_requires = >=3.9
 install_requires =
     more-itertools
     requests