only include wayland in devshell on macos

linux/nix/devshell.nix

@@ -18,12 +18,13 @@ let
   };
 in
 pkgs.mkShell {
-  packages = with pkgs; [
+  packages =
+    with pkgs;
+    [
       go
       git
       jdk17
       libGL
-    wayland
       (flutter.override {
         extraPkgConfigPackages = [
           mpv-unwrapped
@@ -31,6 +32,9 @@ pkgs.mkShell {
         ];
       })
       android.platform-tools
+    ]
+    // lib.optionals pkgs.stdenv.isLinux [
+      wayland
     ];
 
   env = rec {