fix classifier of amplpy v0.16.0

Author: jurgen-lentz

setup.py

@@ -203,7 +203,7 @@ def link_args():
         "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: 3.13",
         "Programming Language :: Python :: 3.14",
-        "Programming Language :: Python :: 3.14t",
+        "Programming Language :: Python :: Free Threading :: 2 - Beta",
         "Programming Language :: Python :: Implementation :: CPython",
     ],
     packages=["amplpy"],