chore(pyproject): modernize Python version and license metadata (#897)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: tschm

pyproject.toml

@@ -22,12 +22,10 @@ classifiers = [
   "Intended Audience :: Science/Research",
   "Topic :: Office/Business :: Financial",
   "Topic :: Scientific/Engineering :: Mathematics",
-  "Programming Language :: Python :: 3 :: Only",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
   "Programming Language :: Python :: 3.14",
-  "License :: OSI Approved :: MIT License",
 ]
 
 # Project URLs for documentation and reference