Drop Python 3.8 support, add 3.13

Author: nicoddemus

setup.py

@@ -32,11 +32,11 @@
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.8",
         "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",
         "Topic :: Desktop Environment :: Window Managers",
         "Topic :: Software Development :: Quality Assurance",
         "Topic :: Software Development :: Testing",