fix(packages): Fix last remaining issues reported by nix flake check

* Add `autoPatchelfHook` to `nativeBuildInputs` only when compiling for Linux
* Correctly specify the list of supported platforms for `rapidsnark-server`

Author: PetarKirov

packages/rapidsnark-server/default.nix

@@ -1,4 +1,5 @@
 {
+  lib,
   stdenv,
   pistache,
   ffiasm,
@@ -9,7 +10,12 @@
 in
   stdenv.mkDerivation rec {
     pname = "rapidsnark-server";
-    inherit (rapidsnark) version src nativeBuildInputs doCheck meta;
+    inherit (rapidsnark) version src nativeBuildInputs doCheck;
+    meta =
+      rapidsnark.meta
+      // {
+        platforms = with lib.platforms; linux;
+      };
     buildInputs = rapidsnark.buildInputs ++ [pistache];
 
     buildPhase = ''

packages/solana-bpf-tools/default.nix

@@ -10,7 +10,7 @@ with pkgs;
     };
 
     # TODO autoPatchElf is Linux-specific. We need a cross-platform solution.
-    nativeBuildInputs = [autoPatchelfHook];
+    nativeBuildInputs = lib.optionals stdenv.isLinux [autoPatchelfHook];
 
     buildInputs = with pkgs; [
       zlib

packages/wasmd/default.nix

@@ -35,7 +35,7 @@ in
 
     subPackages = ["cmd/wasmd"];
 
-    buildInputs = [autoPatchelfHook];
+    nativeBuildInputs = lib.optionals stdenv.isLinux [autoPatchelfHook];
 
     postBuild = ''
       mkdir -p "$out/lib"