Removed license classifier in favor of SPDX entry.

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools >= 61.0"]
+requires = ["setuptools >= 77.0"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -24,11 +24,10 @@ readme = "README.rst"
 authors = [
     {name = "gryf", email = "gryf73@gmail.com"}
 ]
-license = {text = "GPLv3"}
+license = "GPL-3.0-or-later"
 classifiers = [
     "Environment :: Console",
     "Intended Audience :: Other Audience",
-    "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
     "Operating System :: POSIX :: Linux",
     "Development Status :: 3 - Alpha",
     "Programming Language :: Python",