## Description of bug
emacs can't load packages installed by guix because missing
$GUIX_PROFILE/share/emacs/site-lisp
in EMACSLOADPATH

$GUIX_PROFILE/share/emacs/site-lisp isn't set in my
$GUIX_PROFILE/etc/profile and not in my $EMACSLOADPATH

```
$ echo $EMACSLOADPATH
/run/current-system/profile/share/emacs/site-lisp:/run/current-system/profile/share/emacs/27.1/lisp

$ less $GUIX_PROFILE/etc/profile
export EMACSLOADPATH="${GUIX_PROFILE:-/gnu/store/vq5dzmbx202z9p5hjyxfzcdpyzapxgxg-profile}/share/emacs/site-lisp:${GUIX_PROFILE:-/gnu/store/vq5dzmbx202z9p5hjyxfzcdpyzapxgxg-profile}/share/emacs/27.1/lisp${EMACSLOADPATH:+:}$EMACSLOADPATH"

```

## Workaround used
add in init.el
```
(add-to-list 'load-path "/home/dev_1/.guix-profile/share/emacs/site-lisp")
(guix-emacs-autoload-packages)
```
## version
emacs 27.1