Include license info according to PEP-639

Author: ZipFile

pyproject.toml

@@ -12,7 +12,8 @@ maintainers = [
 ]
 description = "Dependency injection framework for Python"
 readme = {file = "README.rst", content-type = "text/x-rst"}
-license = {file = "LICENSE.rst", content-type = "text/x-rst"}
+license = "BSD-3-Clause"
+license-files = ["LICENSE.rst"]
 requires-python = ">=3.8"
 keywords = [
     "Dependency injection",
@@ -27,7 +28,6 @@ keywords = [
 classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Intended Audience :: Developers",
-    "License :: OSI Approved :: BSD License",
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",