sdl2-compat: specify as compatible with all platforms

The SDL library has backends for many platforms, not just unix ones,
however, it's currently restricted by its dependencies.

pkgs/by-name/sd/sdl2-compat/package.nix

@@ -44,22 +44,16 @@ stdenv.mkDerivation (finalAttrs: {
 
   outputBin = "dev";
 
+  # SDL3 is dlopened at runtime, leave it in runpath
+  dontPatchELF = true;
+
   cmakeFlags = [
     (lib.cmakeBool "SDL2COMPAT_TESTS" finalAttrs.finalPackage.doCheck)
+    (lib.cmakeFeature "CMAKE_INSTALL_RPATH" (lib.makeLibraryPath [ sdl3 ]))
   ];
 
   doCheck = testSupport && stdenv.buildPlatform.canExecute stdenv.hostPlatform;
 
-  postFixup =
-    if stdenv.hostPlatform.isDarwin then
-      ''
-        install_name_tool -add_rpath ${lib.makeLibraryPath [ sdl3 ]} $out/lib/libSDL2.dylib
-      ''
-    else
-      ''
-        patchelf --add-rpath ${lib.makeLibraryPath [ sdl3 ]} $out/lib/libSDL2.so
-      '';
-
   patches = [ ./find-headers.patch ];
   setupHook = ./setup-hook.sh;
 
@@ -95,7 +89,7 @@ stdenv.mkDerivation (finalAttrs: {
     changelog = "https://github.com/libsdl-org/sdl2-compat/releases/tag/${finalAttrs.src.tag}";
     license = lib.licenses.zlib;
     maintainers = with lib.maintainers; [ nadiaholmquist ];
-    platforms = lib.platforms.unix;
+    platforms = lib.platforms.all;
     pkgConfigModules = [ "sdl2_compat" ];
   };
 })