Merge pull request #329554 from chayleaf/gradle-unwrapped

gradle: expose gradle-unwrapped in passthru

pkgs/development/tools/build-managers/gradle/default.nix

···
       passthru = {
         fetchDeps = callPackage ./fetch-deps.nix { inherit mitm-cache; };
         inherit (gradle) jdk;
+        unwrapped = gradle;
       };
 
       meta = gradle.meta // {