Supply.categorize.done doesn't distribute .done to sub-supplies

categorize-golf.p6

my $s = Supply.new;
$s.tap: {
    say "Outer got ",$_;
}, :done{ say "Outer done" }

$s.categorize({.round}).tap: -> $pair (:$key, :$value){
    say "Categorize produced ", $pair;
    $value.tap: {
        say "Key $key got value ", $_;
    }, :done{ say "Supply for key $key done" }
}, :done{ say "Categorize done" }

$s.emit($_) for 1.2, 4, 2, 0.9, 3.7, 2.3;
$s.done;