Thank you for your comments, they certainly make the issue clearer, but where
I am still confused about how to change this in a useful way. My problem
isn't just what regular expression to use but rather that the one at issue is
part of the defvar of auto-mode-alist that is created when files.el is an
official part of emacs. Of course I can change files.el, but I certainly do
not want to do that. And of course I can just redefine auto-mode-alist
changing only the troublesome part, but again I hope there is a less extreme
solution.