bug#57242: GNOME is missing default font (cantarell)

[Christophe Pisteur]

## Steps to reproduce

The following steps assume you are using Guix System with GNOME desktop.

1. Boot with a 5.18 kernel

2. Connect with GDM / X11 to the Gnome desktop

## Expected result

+ The gnome desktop interface uses the default Cantarell font (as in 5.17 kernel)

+ Cantarell font is available in applications (for example LibreOffice)

## Unexpected result

+ the Cantarell, font which is the default font of the gnome desktop, is not used in the Gnome interface

+ gnome-tweaks, which allows to select the interface font, does not list the Cantarell font

+ Cantarell font is not proposed by LibreOffice 7.5.3 either

see: https://lists.gnu.org/archive/html/help-guix/2022-08/msg00110.html

## Workaround

Thank to https://luis-felipe.gitlab.io/:

1. guix install font-abattis-cantarell

2. fc-cache -rv

3. Reload GNOME Shell (press Alt+F2, type the letter r in the command box, and press Enter)

see: https://lists.gnu.org/archive/html/help-guix/2022-08/msg00115.html

## System information

GNOME 40.4

GNU Guix 8337787

Guix system 64 bit / X11

Kernel 5.18.12, 5.18.14, 5.18.16