gnu: rust-wayland-server-0.28: Adapt for new build system.

gnu: rust-wayland-server-0.28: Adapt for new build system.

* gnu/packages/crates-graphics.scm (rust-wayland-server-0.28)
[arguments]: Don't skip build. Remove rust-wayland-commons-0.28,
rust-wayland-scanner-0.28, rust-wayland-sys-0.28 from cargo-inputs.
[inputs]: Add rust-bitflags-1, rust-downcast-rs-1, rust-lazy-static-1,
rust-libc-0.2, rust-nix-0.18, rust-parking-lot-0.18, rust-scoped-tls-1,
rust-wayland-commons-0.28, rust-wayland-scanner-0.28,
rust-wayland-sys-0.28.
(rust-wayland-server-0.23): Adjust accordingly.