bug#71356: use-package doesn't load org from elpa

[Eli Zaretskii <eliz@gnu.org>]

> From: Pedro Andres Aranda Gutierrez <paaguti@gmail.com>
> Date: Mon, 10 Jun 2024 18:51:08 +0200
> Cc: Philip Kaludercic <philipk@posteo.net>, acorallo@gnu.org, 71356@debbugs.gnu.org
> 
> We don't want to change what :pin means, IMHO we need it to obey `package-install-upgrade-built-in`.
> That wouldn't be incompatible, right?

Right.  But AFAIU, that was not what Philip was proposing.  If I
misunderstood, my apologies.

> So the sketch that actually loads org from elpa would be
> 
> (let ((package-install-upgrade-built-in t))
>   (use-package org
>     :ensure t :pin gnu))

No, you are supposed to customize that option if you want built-in
packages to be upgraded as the rest of them.  You aren't supposed to
let-bind user options.