flatpak: add missing -devel packages to depends

srcpkgs/flatpak/template

@@ -1,7 +1,7 @@
 # Template file for 'flatpak'
 pkgname=flatpak
 version=1.15.9
-revision=1
+revision=2
 build_style=meson
 build_helper="gir"
 configure_args="
@@ -49,7 +49,7 @@ flatpak-devel_package() {
 	short_desc+=" - development files"
 	depends="${sourcepkg}>=${version}_${revision} libglib-devel libostree-devel
 	 libcurl-devel libarchive-devel json-glib-devel dconf-devel libseccomp-devel
-	 gpgme-devel polkit-devel"
+	 gpgme-devel polkit-devel libxml2-devel libXau-devel"
 	pkg_install() {
 		vmove usr/include
 		vmove usr/lib/pkgconfig