Add Python 3.13 classifier

Author: maresb

pyproject.toml

@@ -15,6 +15,7 @@ classifiers = [
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: 3.13",
   "License :: OSI Approved :: Apache Software License",
   "Intended Audience :: Science/Research",
   "Topic :: Scientific/Engineering",