fix: nix evaluation warnings + flake improvements (#395)

* fix: nix evaluation warning

* nix: minor flake improvements/maintenance

* nix: fix macos build errors

* nix: minor cleanup/fixes

* nix: remove redundant deps

* nix: remove reliance on systems input

nix/default.nix

@@ -1,34 +1,40 @@
 {
+  stdenv,
   rustPlatform,
   lib,
-  pkgs,
-}: let
-  cargoToml = builtins.fromTOML (builtins.readFile ../Cargo.toml);
+  pkg-config,
+  libX11,
+  gtk4,
+  libadwaita,
+  libXtst,
+  wrapGAppsHook4,
+  librsvg,
+  git,
+}:
+let
+  cargoToml = fromTOML (builtins.readFile ../Cargo.toml);
   pname = cargoToml.package.name;
   version = cargoToml.package.version;
 in
 rustPlatform.buildRustPackage {
-  pname = pname;
-  version = version;
+  inherit pname;
+  inherit version;
 
-  nativeBuildInputs = with pkgs; [
-    git
+  nativeBuildInputs = [
     pkg-config
-    cmake
-    makeWrapper
-    buildPackages.gtk4
+    wrapGAppsHook4
+    git
   ];
 
-  buildInputs = with pkgs; [
-    xorg.libX11
+  buildInputs = [
     gtk4
     libadwaita
-    xorg.libXtst
-  ] ++ lib.optionals stdenv.isDarwin
-  (with darwin.apple_sdk_11_0.frameworks; [
-    CoreGraphics
-    ApplicationServices
-  ]);
+    librsvg
+  ]
+  ++ lib.optionals stdenv.isLinux [
+    libX11
+    libXtst
+  ];
 
   src = builtins.path {
     name = pname;
@@ -40,11 +46,7 @@ rustPlatform.buildRustPackage {
   # Set Environment Variables
   RUST_BACKTRACE = "full";
 
-  # Needed to enable support for SVG icons in GTK
   postInstall = ''
-    wrapProgram "$out/bin/lan-mouse" \
-      --set GDK_PIXBUF_MODULE_FILE ${pkgs.librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache
-
     install -Dm444 *.desktop -t $out/share/applications
     install -Dm444 lan-mouse-gtk/resources/*.svg -t $out/share/icons/hicolor/scalable/apps
   '';