[bug#41731] [PATCH] gnu: Add emacs-flymake-shellcheck.

[Fredrik Salomonsson via web]

Thanks for the feedback.
I was debating to myself whether to include shellcheck or not. As when I looked 
around in emacs-xyz.scm, for example `emacs-ag' does propagate 
the-silver-searcher but `emacs-direnv' does not.

Anyway, I removed it in the latest patch.