wordgrinder: Fix build

First I tried to fix the build like this:

> This fixes the build of the wordgrinder package by disabling the build
> of "xwordgrinder", the non-curses frontend of wordgrinder.
>
> For re-enabling the build, this patch shall be reverted and then go on
> from there.
>
> I opted for disabling the x frontend of this program because the whole
> purpose of this is to use a curses writing program (at least for me).
> It seems that hacking around the new build system in nixpkgs is a
> non-trivial task and I wanted to get this package out of the door as
> fast as possible because I already delayed the fix by a few days (or is
> it weeks already), so this is the simple fix.
>
> If someone wants to have the X frontend again, I can invest more time at
> some point.

But then the almighty aszlig came around and told me how to do it right. So here
we go, with a patch from me that is acutally from aszlig (see #60122).

This fixes the build.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
Signed-off-by: aszlig <aszlig@nix.build>
Fixes: 6b2bd330 ("wordgrinder: Fix sha256 hash")
Fixes: 19a3abc1 ("wordgrinder: 0.7.1 -> 0.7.2")
Merges: https://github.com/NixOS/nixpkgs/pull/60122
Cc: @devhell