Use date "+%a %b %d %Y" for RPM changelog entries

See https://bgstack15.wordpress.com/2016/11/29/date-format-for-rpm-changelog/

Author: pepone

ice/rpm/ice-aix.spec

@@ -588,7 +588,7 @@ mv %{buildroot}%{_bindir}/icebox32 %{buildroot}%{_bindir}/icebox_32
 %endif
 
 %changelog
-* Tue March 14 2023 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.9
+* Tue Mar 14 2023 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.9
 - 3.7.9 release
 
 * Tue Jun 27 2022 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.8

ice/rpm/ice.spec

@@ -899,7 +899,7 @@ exit 0
 %endif #%{_host_cpu}
 
 %changelog
-* Tue March 14 2023 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.9
+* Tue Mar 14 2023 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.9
 - 3.7.9 release
 
 * Mon Jun 27 2022 José Gutiérrez de la Concha <jose@zeroc.com> 3.7.8