build: drop deprecated License classifier (use SPDX license expression)

setuptools (PEP 639) rejects the 'License :: OSI Approved' classifier when a
SPDX 'license' expression is set, which broke the editable install in CI.

Author: opensource-SantanderAI

pyproject.toml

@@ -18,7 +18,6 @@ classifiers = [
     "Development Status :: 4 - Beta",
     "Intended Audience :: Developers",
     "Intended Audience :: Science/Research",
-    "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",