Add Trove classifier for Python 3.15 (#213)

Author: hugovk

src/trove_classifiers/__init__.py

@@ -526,6 +526,7 @@
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
     "Programming Language :: Python :: Implementation",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: IronPython",