Remove deprecated license metadata (#221)

Author: Cadair

pyproject.toml

@@ -19,7 +19,6 @@ authors = [
 classifiers = [
   "Development Status :: 3 - Alpha",
   "Intended Audience :: Science/Research",
-  "License :: OSI Approved :: BSD License",
   "Natural Language :: English",
   "Operating System :: OS Independent",
   "Programming Language :: Python",