main/postmarketos-ui-gnome: set pmOS wallpaper (MR 4527)

Set myself as maintainer while at it, as Martijn is currently inactive.

main/postmarketos-ui-gnome/APKBUILD

@@ -1,8 +1,8 @@
 # Reference: https://postmarketos.org/uipkg
-# Maintainer: Martijn Braam <martijn@brixit.nl>
+# Maintainer: Oliver Smith <ollieparanoid@postmarketos.org>
 pkgname=postmarketos-ui-gnome
 pkgver=3
-pkgrel=5
+pkgrel=6
 pkgdesc="(Wayland) Gnome Shell"
 url="https://gnome.org/"
 # armhf blocked by gnome-shell -> gjs -> mozjs102
@@ -17,6 +17,7 @@ depends="
 	gnome
 	kgx
 	postmarketos-base-ui-gnome
+	postmarketos-base-ui-gnome-wallpaper-pmos
 	xwayland
 	"
 install="$pkgname.post-install $pkgname.post-upgrade"