convert license to SPDX

This is part of https://fedoraproject.org/wiki/Changes/SPDX_Licenses_Phase_4

alligator.spec

@@ -1,7 +1,8 @@
 Name:           alligator 
 Version:        24.05.2
-Release:        2%{?dist}
-License:        GPLv2 or GPLv3
+Release:        3%{?dist}
+# Automatically converted from old format: GPLv2 or GPLv3 - review is highly recommended.
+License:        GPL-2.0-only OR GPL-3.0-only
 Summary:        Kirigami-based RSS reader
 Url:            https://invent.kde.org/network/alligator
 Source:         https://download.kde.org/%{stable_kf6}/release-service/%{version}/src/%{name}-%{version}.tar.xz
@@ -65,6 +66,9 @@ desktop-file-validate %{buildroot}%{_datadir}/applications/org.kde.%{name}.deskt
 
 
 %changelog
+* Wed Aug 07 2024 Miroslav Suchý <msuchy@redhat.com> - 24.05.2-3
+- convert license to SPDX
+
 * Wed Jul 17 2024 Fedora Release Engineering <releng@fedoraproject.org> - 24.05.2-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild