main/postmarketos-ui-phosh: add xdg-desktop-portal-wlr (MR 4334)

Since it's the recommended for the screencast feature
https://gitlab.gnome.org/World/Phosh/phosh/-/merge_requests/1301

[ci:skip-build]: Already built successfully in CI.

main/postmarketos-ui-phosh/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Newbyte <newbyte@postmarketos.org>
 pkgname=postmarketos-ui-phosh
 pkgver=22.3
-pkgrel=2
+pkgrel=3
 pkgdesc="(Wayland) Mobile UI initially developed for the Librem 5"
 url="https://phosh.mobi"
 arch="noarch !armhf"
@@ -24,6 +24,7 @@ depends="
 	tinydm
 	tinydm-openrc
 	udiskie
+	xdg-desktop-portal-wlr
 	"
 _pmb_recommends="
 	calls