casks: Add zap stanza comment

[why]
Casks without zap stanza are flagged; all casks should contain them.

The font casks do not really need zap.

[how]
What is the right way to say 'we considered zap, but do not need it'?

It seems that other people add a comment (the same comment).
For example here:
Homebrew/homebrew-cask#119090

And that seems rather widespread.

        git/homebrew-cask/Casks$ git grep '# No zap stanza required' | wc -l
        101

Include the same in our casks.

[note]
Homebrew/homebrew-cask#88469

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

bin/scripts/generate-casks.sh

@@ -197,6 +197,7 @@ function write_footer {
     local outputfile=$1
 
     {
+        printf "\\n  # No zap stanza required\\n"
         printf "end\\n"
     } >> "$outputfile"
 }