generate.pl: temporarily skip generating for older Perls

Appease test failures for now so we can expedite releasing
5.28.3/5.30.3.

Author: zakame

generate.pl

@@ -5,6 +5,7 @@
 use YAML::XS;
 use Devel::PatchPerl;
 use LWP::Simple;
+use version 0.77;
 
 sub die_with_sample {
   die <<EOF;
@@ -102,6 +103,7 @@ sub die_with_sample {
 }
 
 for my $release (@{$config->{releases}}) {
+  next unless version->parse($release->{version}) >= version->parse('5.28.0');
   do { die_with_sample unless $release->{$_} }
     for (qw(version sha256));