apkbuild-cpan: include modules that used to be part of core

we need to check if a given module currently is a part of core. Modules
which have a first_release may have been removed later, for example
Module::Build.

apkbuild-cpan.in

@@ -125,7 +125,8 @@ sub parse_deps {
 	my $deps = "";
 
 	for my $module ($reqs->required_modules) {
-		if (my $perlver = Module::CoreList->first_release($module)) {
+		if (Module::CoreList->is_core($module)) {
+			my $perlver = Module::CoreList->first_release($module);
 			say "$module is part of core perl since $perlver.";
 			next;
 		}