nix: Fix dev shell on Darwin (#58032)

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [ ] Unsafe blocks (if any) have justifying comments
- [ ] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [ ] Tests cover the new/changed behavior
- [ ] Performance impact has been considered and is acceptable

Release Notes:

- N/A

nix/modules/devshells.nix

@@ -37,7 +37,9 @@
         name = "zed-editor-dev";
         inputsFrom = [ zed-editor ];
 
-        packages = with pkgs; [
+        packages =
+          with pkgs;
+          [
             wrappedCargo # must be first, to shadow the `cargo` provided by `rustToolchain`
             rustToolchain # cargo, rustc, and rust-toolchain.toml components included
             cargo-nextest
@@ -59,8 +61,8 @@
               ps.pyatspi
               ps.pygobject3
             ]))
-          accerciser
-        ];
+          ]
+          ++ lib.optionals stdenv.hostPlatform.isLinux [ accerciser ];
 
         env =
           (removeAttrs baseEnv [