Revert "cosmic-settings: use mold linker"

This reverts commit d9344e9f67.

In Nixpkgs, we consider the linker a property of the platform.
Individual packages should not be using toolchains other than the ones
that are part of the platform without a strong justification.  In this
case, the only justification appears to have been that upstream uses
this linker.  Just like we don't force every package whose upstream
happens to use Clang in their own builds to build with Clang in
Nixpkgs rather than the platform compiler, upstream's choice alone
isn't grounds for overriding the platform linker here.

pkgs/by-name/co/cosmic-settings/package.nix

@@ -1,7 +1,6 @@
 {
   lib,
   stdenv,
-  stdenvAdapters,
   fetchFromGitHub,
   rustPlatform,
   cmake,
@@ -19,90 +18,83 @@
   cosmic-randr,
   xkeyboard_config,
   nix-update-script,
-
-  withMoldLinker ? stdenv.targetPlatform.isLinux,
 }:
 let
   libcosmicAppHook' = (libcosmicAppHook.__spliced.buildHost or libcosmicAppHook).override {
     includeSettings = false;
   };
 in
-rustPlatform.buildRustPackage.override
-  { stdenv = if withMoldLinker then stdenvAdapters.useMoldLinker stdenv else stdenv; }
-  (finalAttrs: {
-    pname = "cosmic-settings";
-    version = "1.0.0-alpha.6";
+rustPlatform.buildRustPackage (finalAttrs: {
+  pname = "cosmic-settings";
+  version = "1.0.0-alpha.6";
 
-    src = fetchFromGitHub {
-      owner = "pop-os";
-      repo = "cosmic-settings";
-      tag = "epoch-${finalAttrs.version}";
-      hash = "sha256-UKg3TIpyaqtynk6wLFFPpv69F74hmqfMVPra2+iFbvE=";
-    };
+  src = fetchFromGitHub {
+    owner = "pop-os";
+    repo = "cosmic-settings";
+    tag = "epoch-${finalAttrs.version}";
+    hash = "sha256-UKg3TIpyaqtynk6wLFFPpv69F74hmqfMVPra2+iFbvE=";
+  };
 
-    useFetchCargoVendor = true;
-    cargoHash = "sha256-mf/Cw3/RLrCYgsk7JKCU2+oPn1VPbD+4JzkUmbd47m8=";
+  useFetchCargoVendor = true;
+  cargoHash = "sha256-mf/Cw3/RLrCYgsk7JKCU2+oPn1VPbD+4JzkUmbd47m8=";
 
-    nativeBuildInputs = [
-      cmake
-      just
-      libcosmicAppHook'
-      pkg-config
-      rustPlatform.bindgenHook
-      util-linux
+  nativeBuildInputs = [
+    cmake
+    just
+    libcosmicAppHook'
+    pkg-config
+    rustPlatform.bindgenHook
+    util-linux
+  ];
+
+  buildInputs = [
+    expat
+    fontconfig
+    freetype
+    libinput
+    pipewire
+    pulseaudio
+    udev
+  ];
+
+  dontUseJustBuild = true;
+  dontUseJustCheck = true;
+
+  justFlags = [
+    "--set"
+    "prefix"
+    (placeholder "out")
+    "--set"
+    "bin-src"
+    "target/${stdenv.hostPlatform.rust.cargoShortTarget}/release/cosmic-settings"
+  ];
+
+  preFixup = ''
+    libcosmicAppWrapperArgs+=(
+      --prefix PATH : ${lib.makeBinPath [ cosmic-randr ]}
+      --set-default X11_BASE_RULES_XML ${xkeyboard_config}/share/X11/xkb/rules/base.xml
+      --set-default X11_BASE_EXTRA_RULES_XML ${xkeyboard_config}/share/X11/xkb/rules/extra.xml
+    )
+  '';
+
+  passthru.updateScript = nix-update-script {
+    extraArgs = [
+      "--version"
+      "unstable"
+      "--version-regex"
+      "epoch-(.*)"
     ];
+  };
 
-    buildInputs = [
-      expat
-      fontconfig
-      freetype
-      libinput
-      pipewire
-      pulseaudio
-      udev
+  meta = {
+    description = "Settings for the COSMIC Desktop Environment";
+    homepage = "https://github.com/pop-os/cosmic-settings";
+    license = lib.licenses.gpl3Only;
+    mainProgram = "cosmic-settings";
+    maintainers = with lib.maintainers; [
+      nyabinary
+      HeitorAugustoLN
     ];
-
-    dontUseJustBuild = true;
-    dontUseJustCheck = true;
-
-    justFlags = [
-      "--set"
-      "prefix"
-      (placeholder "out")
-      "--set"
-      "bin-src"
-      "target/${stdenv.hostPlatform.rust.cargoShortTarget}/release/cosmic-settings"
-    ];
-
-    env."CARGO_TARGET_${stdenv.hostPlatform.rust.cargoEnvVarTarget}_RUSTFLAGS" =
-      lib.optionalString withMoldLinker "-C link-arg=-fuse-ld=mold";
-
-    preFixup = ''
-      libcosmicAppWrapperArgs+=(
-        --prefix PATH : ${lib.makeBinPath [ cosmic-randr ]}
-        --set-default X11_BASE_RULES_XML ${xkeyboard_config}/share/X11/xkb/rules/base.xml
-        --set-default X11_BASE_EXTRA_RULES_XML ${xkeyboard_config}/share/X11/xkb/rules/extra.xml
-      )
-    '';
-
-    passthru.updateScript = nix-update-script {
-      extraArgs = [
-        "--version"
-        "unstable"
-        "--version-regex"
-        "epoch-(.*)"
-      ];
-    };
-
-    meta = {
-      description = "Settings for the COSMIC Desktop Environment";
-      homepage = "https://github.com/pop-os/cosmic-settings";
-      license = lib.licenses.gpl3Only;
-      mainProgram = "cosmic-settings";
-      maintainers = with lib.maintainers; [
-        nyabinary
-        HeitorAugustoLN
-      ];
-      platforms = lib.platforms.linux;
-    };
-  })
+    platforms = lib.platforms.linux;
+  };
+})