Update wayland-rs to 0.30.0

This update rewrites the winit's Wayland backend using new wayland-rs
0.30 API. This fixes long standing issue with the forward compatibility
of the wayland backend, meaning that future updates to the wayland
protocol won't break rust code anymore. like it was before when adding
new shm/enum variants into the protocol.

Fixes #2560.
Fixes #2164.
Fixes #2128.
Fixes #1760.
Fixes #725.

build.rs

@@ -1,35 +1,8 @@
 use cfg_aliases::cfg_aliases;
 
-#[cfg(all(
-    any(
-        target_os = "linux",
-        target_os = "dragonfly",
-        target_os = "freebsd",
-        target_os = "openbsd",
-        target_os = "netbsd",
-    ),
-    feature = "wayland",
-))]
-mod wayland {
-    use std::env;
-    use std::path::PathBuf;
-    use wayland_scanner::Side;
-
-    pub fn main() {
-        let mut path = PathBuf::from(env::var("OUT_DIR").unwrap());
-        path.push("fractional_scale_v1.rs");
-        wayland_scanner::generate_code(
-            "wayland_protocols/fractional-scale-v1.xml",
-            &path,
-            Side::Client,
-        );
-    }
-}
-
 fn main() {
     // The script doesn't depend on our code
     println!("cargo:rerun-if-changed=build.rs");
-    println!("cargo:rerun-if-changed=wayland_protocols");
 
     // Setup cfg aliases
     cfg_aliases! {
@@ -48,17 +21,4 @@ fn main() {
         wayland_platform: { all(feature = "wayland", free_unix, not(wasm), not(redox)) },
         orbital_platform: { redox },
     }
-
-    // XXX aliases are not available for the build script itself.
-    #[cfg(all(
-        any(
-            target_os = "linux",
-            target_os = "dragonfly",
-            target_os = "freebsd",
-            target_os = "openbsd",
-            target_os = "netbsd",
-        ),
-        feature = "wayland",
-    ))]
-    wayland::main();
 }