(debug): Don't `kill-emacs` upon exit when in batch mode

(debug): Don't `kill-emacs` upon exit when in batch mode

AFAICT this is a left over code from many years ago before
the `debug` special case was added to `condition-case` and
at a time where exiting from `debug` did not proceed to handle
remaining handlers.

In the usual case where we indeed want to kill Emacs,
`signal_or_quit` does it for us.

* lisp/emacs-lisp/debug.el (debug): Don't `kill-emacs` upon exit
when in batch mode (bug#76786)

(cherry picked from commit 82affcaeff8b7a0ed1f30adbf5905f934c4cebaf)