sbt-with-scala-native: use `overrideAttrs` to fix `nativeBuildInputs` splicing

preserve old nativeBuildInputs which includes autoPatchelfHook which was
not there when this override was added

drop the `sha256` and `version` overrides which have never worked
properly because they haven't been overriding src.

`sha256` and `version` were added in 49c7bed76385ab46d5e0f76b2f26f17a2c7d3658

pkgs/development/tools/build-managers/sbt/scala-native.nix

···
 { lib, sbt, makeWrapper, boehmgc, libunwind, re2, llvmPackages, zlib }:
 
-sbt.overrideDerivation(old: {
-  nativeBuildInputs = [ makeWrapper ];
-
-  version = "0.13.16";
-
-  sha256 = "033nvklclvbirhpsiy28d3ccmbm26zcs9vb7j8jndsc1ln09awi2";
+sbt.overrideAttrs(previousAttrs: {
+  nativeBuildInputs = (previousAttrs.nativeBuildInputs or [ ]) ++ [ makeWrapper ];
 
-  postFixup = ''
+  postFixup = (previousAttrs.postFixup or "") + ''
     wrapProgram $out/bin/sbt \
       --set CLANG_PATH      "${llvmPackages.clang}/bin/clang" \
       --set CLANGPP_PATH    "${llvmPackages.clang}/bin/clang" \