Don't recommend code that does not work

Please revert once RT #132016 is resolved.

doc/Type/Proc/Async.pod6

@@ -14,6 +14,10 @@ moment.
 C<Proc::Async> allows you to run external commands asynchronously, capturing
 standard output and error handles, and optionally write to its standard input.
 
+=begin comment
+⚠ Revert the commit mentioned in RT #132016 once it is resolved
+=end comment
+
     my $file = ‘foo’.IO;
     spurt $file, “and\nCamelia\n♡\nme\n”;
 
@@ -34,11 +38,11 @@ standard output and error handles, and optionally write to its standard input.
         whenever $proc.print: “I\n♥\nCamelia\n” {
             $proc.close-stdin
         }
-        whenever signal(SIGTERM).merge: signal(SIGINT) {
+        whenever signal(SIGTERM) {
             once {
                 say ‘Signal received, asking the process to stop’;
                 $proc.kill; # send SIGHUP
-                whenever signal($_).zip: Promise.in(2).Supply {
+                whenever signal($_) {
                     say ‘Kill it!’;
                     $proc.kill: SIGKILL
                 }