convert GPLv3 license to SPDX

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

R-mockr.spec

@@ -4,10 +4,11 @@
 
 Name:             R-%{packname}
 Version:          0.2.1
-Release:          8%{?dist}
+Release:          9%{?dist}
 Summary:          Mocking in R
 
-License:          GPLv3
+# Automatically converted from old format: GPLv3 - review is highly recommended.
+License:          GPL-3.0-only
 URL:              https://CRAN.R-project.org/package=%{packname}
 Source0:          https://cran.r-project.org/src/contrib/%{packname}_%{version}.tar.gz
 
@@ -74,6 +75,9 @@ _R_CHECK_FORCE_SUGGESTS_=0 %{_bindir}/R CMD check %{packname} --ignore-vignettes
 %{rlibdir}/%{packname}/doc
 
 %changelog
+* Mon Jul  29 2024 Miroslav Suchý <msuchy@redhat.com> - 0.2.1-9
+- convert license to SPDX
+
 * Wed Jul 17 2024 Fedora Release Engineering <releng@fedoraproject.org> - 0.2.1-8
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild