cleanup bundler exclusions during jruby unpacking (elastic#12692)

JRuby had a few releases where it shipped with bundler,
creating some difficulty in working with newer versions.
This no longer happens so we can remove these exclusions
from the jruby unzipping task.

rubyUtils.gradle

@@ -272,10 +272,6 @@ tasks.register("downloadAndInstallJRuby", Copy) {
         f.path = f.path.replaceFirst("^jruby-${jRubyVersion}", '')
     }
     exclude "**/stdlib/rdoc/**"
-    exclude "**/stdlib/bundler/**"
-    exclude "**/stdlib/bundler.rb"
-    exclude "**/bundler-1.16.6/**"
-    exclude "**/bundler-1.16.6.*"
     exclude "**/did_you_mean-*/evaluation/**" // licensing issue https://github.com/jruby/jruby/issues/6471
 
     includeEmptyDirs = false