Remove fix to use rake-compiler-dock on Windows for libiconv

The original author states that the code I removed is for using virtualbox on Windows to compile the gem. I read up on this and while rake-compiler-dock still supports using docker-machine to compile gems, the project has been discontinued in favor of Docker Desktop, which nowadays only works with Docker in WSL2.

Author: andyundso

tasks/ports/libiconv.rb

@@ -8,25 +8,8 @@ def initialize(version)
       set_patches
     end
 
-    def cook
-      chdir_for_build do
-        super
-      end
-      self
-    end
-
     private
 
-    # When using rake-compiler-dock on Windows, the underlying Virtualbox shared
-    # folders don't support symlinks, but libiconv expects it for a build on
-    # Linux. We work around this limitation by using the temp dir for cooking.
-    def chdir_for_build
-      build_dir = ENV['RCD_HOST_RUBY_PLATFORM'].to_s =~ /mingw|mswin|cygwin/ ? '/tmp' : '.'
-      Dir.chdir(build_dir) do
-        yield
-      end
-    end
-
     def configure_defaults
       [
         "--host=#{@host}",