SPDX migration

According to LICENSE, some files are licensed under the PSF-2.0 license,
so let's add it.

python-greenlet.spec

@@ -2,9 +2,9 @@
 
 Name:           python-%{modname}
 Version:        2.0.2
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        Lightweight in-process concurrent programming
-License:        MIT
+License:        MIT AND PSF-2.0
 URL:            https://github.com/python-greenlet/greenlet
 Source0:        %{url}/archive/%{version}/%{modname}-%{version}.tar.gz
 
@@ -74,6 +74,9 @@ PYTHONPATH="%{buildroot}%{python3_sitearch}" \
 %{_includedir}/python%{python3_version}*/%{modname}/
 
 %changelog
+* Sat Aug 05 2023 Ondřej Budai <ondrej@budai.cz> - 2.0.2-3
+- SPDX migration
+
 * Fri Jul 21 2023 Fedora Release Engineering <releng@fedoraproject.org> - 2.0.2-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild