Update to zbus 5.x

https://github.com/dbus2/zbus/releases/tag/zbus-5.0.0

Now requires `pub` on uses of `#[proxy]` if the generated types should
be `pub`.

mpris2/src/bindings/media_player.rs

@@ -26,7 +26,7 @@ use zbus::proxy;
 	interface = "org.mpris.MediaPlayer2",
 	default_path = "/org/mpris/MediaPlayer2"
 )]
-trait MediaPlayer2 {
+pub trait MediaPlayer2 {
 	/// Quit method
 	fn quit(&self) -> zbus::Result<()>;
 

mpris2/src/bindings/player.rs

@@ -27,7 +27,7 @@ use zbus::proxy;
 	interface = "org.mpris.MediaPlayer2.Player",
 	default_path = "/org/mpris/MediaPlayer2"
 )]
-trait Player {
+pub trait Player {
 	/// Next method
 	fn next(&self) -> zbus::Result<()>;
 

mpris2/src/bindings/playlist.rs

@@ -26,7 +26,7 @@ use zbus::proxy;
 	interface = "org.mpris.MediaPlayer2.Playlists",
 	default_path = "/org/mpris/MediaPlayer2"
 )]
-trait Playlists {
+pub trait Playlists {
 	/// ActivatePlaylist method
 	fn activate_playlist(&self, playlist_id: &PlaylistId) -> zbus::Result<()>;
 

mpris2/src/bindings/track_list.rs

@@ -26,7 +26,7 @@ use zbus::proxy;
 	interface = "org.mpris.MediaPlayer2.TrackList",
 	default_path = "/org/mpris/MediaPlayer2"
 )]
-trait TrackList {
+pub trait TrackList {
 	/// AddTrack method
 	fn add_track(&self, uri: &str, after_track: &TrackId, set_as_current: bool)
 		-> zbus::Result<()>;

mpris2/src/playlists/ordering.rs

@@ -25,9 +25,7 @@ pub enum PlaylistOrdering {
 }
 
 impl Type for PlaylistOrdering {
-	fn signature() -> Signature<'static> {
-		String::signature()
-	}
+	const SIGNATURE: &'static Signature = String::SIGNATURE;
 }
 
 impl<'a> TryFrom<Value<'a>> for PlaylistOrdering {