Use PEP 639 licensing metadata

Author: auscompgeek

.github/workflows/pythonpackage.yml

@@ -64,4 +64,4 @@ jobs:
         name: Packages
         path: dist
     - name: Publish to PyPI
-      uses: pypa/gh-action-pypi-publish@v1.6.11
+      uses: pypa/gh-action-pypi-publish@v1.12.4

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["flit_core >=3.2,<4"]
+requires = ["flit_core >=3.11,<4"]
 build-backend = "flit_core.buildapi"
 
 [project]
@@ -8,15 +8,15 @@ authors = [
 	{ name = "David Vo", email = "[email protected]" },
 ]
 readme = "README.md"
-license = { file = "LICENSE" }
+license = "BSD-3-Clause"
+license-files = ["LICENSE"]
 requires-python = ">=3.6"
 dependencies = [
 	"dataclasses; python_version < '3.7'",
 ]
 classifiers = [
 	"Development Status :: 5 - Production/Stable",
 	"Intended Audience :: Developers",
-	"License :: OSI Approved :: BSD License",
 	"Operating System :: OS Independent",
 	"Programming Language :: Python :: 3",
 	"Programming Language :: Python :: 3 :: Only",