Add missing entry for 3.13

Author: parthea

setup.py

@@ -86,6 +86,7 @@
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "Programming Language :: Python :: 3.14",
         "Operating System :: OS Independent",
         "Topic :: Internet",