See Scope::Guard, which is designed to do exactly that, you create it with a subroutine to run when it goes out of scope...

use strict; use warnings;
use Scope::Guard;
sub foo {
    my $blah = shift;
    my $sg = Scope::Guard->new( sub {
        print "This runs at the end of the scope\n";
    } );
    print "Doing some other stuff now...\n";
}
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