bug#61929: Stuff after commas oddly colored in Shell-script mode

[Eli Zaretskii]

> From: Dan Jacobson <jidanni@jidanni.org>
> Date: Fri, 03 Mar 2023 12:59:32 +0800
> 
> Shell-script mode defined in sh-script.el,
> gives odd colored stuff after commas:
> $ cat x.sh
> gpsbabel -i kml -f $1 \
>        -x nuketypes,waypoints -x interpolate,time=1 \
>        -x track,start=$2,stop=$2 -o xcsv,style=x.style -F -
> $ emacs -Q x.sh
> emacs-version "28.2"

Upgrade to Emacs 29 and use bash-ts-mode instead, then these problems
will go away.