gnome-font-viewer: needs gettext in hostmakedepends.

This also fixes the lack of desktop file, as package installs translated file
which was getting ignored when gettext was not found on the host system:
https://gitlab.gnome.org/GNOME/gnome-font-viewer/-/blob/1e5b/src/meson.build#L42

srcpkgs/gnome-font-viewer/template

@@ -1,9 +1,9 @@
 # Template file for 'gnome-font-viewer'
 pkgname=gnome-font-viewer
 version=40.0
-revision=1
+revision=2
 build_style=meson
-hostmakedepends="pkg-config glib-devel"
+hostmakedepends="pkg-config glib-devel gettext"
 makedepends="fontconfig-devel freetype-devel glib-devel gtk+3-devel
  gnome-desktop-devel harfbuzz-devel libhandy1-devel"
 depends="desktop-file-utils"