bug#55655: 28.1; package.el no longers respects `user-emacs-directory'

[Eli Zaretskii <eliz@gnu.org>]

> From: Shitikanth <shitikanth1@gmail.com>
> Date: Thu, 26 May 2022 16:37:48 +0530
> 
> Until emacs 27.2, package.el used to correctly pick `package-user-dir'
> based on the value of `user-emacs-directory', but it now seems to ignore
> it and defaults to "~/.emacs.d/elpa".
> 
> Demo:
>     (setq user-emacs-directory "/tmp")
>     (require 'package)
>     (message "%s" package-user-dir)
> 
> Starting with "emacs -Q" this would output "~/.emacs.d/elpa".
> Expected output: "/tmp/elpa" (as in emacs 27.2).
> 
> Based on git bisect, the offending commit seems to be 9973019764.

Why do you set user-emacs-directory instead of setting
package-user-dir directly?  You are supposed to set the latter in your
early-init file.