gnome-session: revert to pkg-config

[ci skip]

srcpkgs/gnome-session/template

@@ -1,10 +1,10 @@
 # Template file for 'gnome-session'
 pkgname=gnome-session
 version=3.30.1
-revision=2
+revision=3
 build_style=meson
 configure_args="-Dsystemd_journal=false"
-hostmakedepends="glib-devel intltool pkgconf xmlto"
+hostmakedepends="glib-devel intltool pkg-config xmlto"
 makedepends="elogind-devel gnome-desktop-devel gtk+3-devel json-glib-devel
  libglib-devel libICE-devel libSM-devel libXtst-devel startup-notification-devel
  upower-devel xtrans"