javaPackages: cleanup unused code

pkgs/development/compilers/temurin-bin/jdk-linux-base.nix

···
   providedCpuTypes = builtins.filter
     (arch: builtins.elem arch validCpuTypes)
     (builtins.attrNames sourcePerArch);
-  result = stdenv.mkDerivation rec {
+  result = stdenv.mkDerivation {
     pname = if sourcePerArch.packageType == "jdk"
       then "${name-prefix}-bin"
       else "${name-prefix}-${sourcePerArch.packageType}-bin";

pkgs/top-level/java-packages.nix

···
       package = if stdenv.isLinux
         then package-linux
         else package-darwin;
-    in rec {
+    in {
       inherit package-linux package-darwin;
 
       jdk-hotspot = callPackage package.jdk-hotspot {};
···
       headless = openjdk.override { headless = true; };
     };
 
-    openjdkDarwinMissing = version:
-      abort "OpenJDK ${builtins.toString version} is currently not supported on Darwin by nixpkgs.";
-
   in rec {
-
     adoptopenjdk-8 = mkAdoptopenjdk
       ../development/compilers/adoptopenjdk-bin/jdk8-linux.nix
       ../development/compilers/adoptopenjdk-bin/jdk8-darwin.nix;