Re: [PATCH v5 0/8] you-still-use-that??: improve breaking changes troubleshooting

> Draft of the commit message:
>
> -----
>
> Makefile: don’t add whatchanged after it has been removed
>
> 07572f220a8 (whatchanged: remove when built with WITH_BREAKING_CHANGES,
> 2025-05-12) set up the removal of git-whatchanged(1) when
> `WITH_BREAKING_CHANGES` is active.  Part of that work was removing it
> from `commands` in `git.c`.  But the the Makefile still lists it as a
> builtin .  That leaves it in the limbo of being linked but not being
> callable; you get the generic error about not being able to call it as
> a *builtin*:
>
>     $ git whatchanged
>     fatal: cannot handle whatchanged as a builtin
>
> instead of the expected:
>
>     $ git whatchanged
>     git: 'whatchanged' is not a git command. See 'git --help'.