bug#59914: [GNU ELPA] Make use-package and bind-key into :core packages

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

>> Can we use "lisp/use-package/" (and maybe the use `:ignored-files` to
>> strip out `bind-keys.el` or maybe even move `bind-keys.el` outside of
>> the `use-package` subdirectory)?
> I think we could move bind-keys to lisp/emacs-lisp, if everybody agrees.

[ I don't have an opinion on this.  ]

>>> + ("use-package-ensure-system-package"
>>> +  :core ("lisp/use-package/use-package-ensure-system-package.el"))
>> Why do we need this as a separate package?
> Because it was like that on MELPA.

Doesn't sound like a strong enough reason.

> I think we might as well not do that.

I'm glad you agree.

> The only nice thing I see is that it would stop `use-package' from
> depending on `system-packages'.  But I don't think that's a big issue,
> and on the contrary doing that will make things simpler.

We can include `use-package-ensure-system-package.el` without adding
a dependency on `system-packages`.  Just like `use-package` did not
depend on `use-package-ensure-system-package` in MELPA.
[ Or just like Emacs itself now includes `use-package` and
  `use-package-ensure-system-package.el` but not `system-packages`.  ]

The patch looks good to me, feel free to push,


        Stefan