Don't install libffi-6 with ruby 3.2

Previously, we were copying libffi-6.dll to both ruby 2.7 and 3.2 bin directories
on Windows:

    $ find . -type f -name "libffi*dll"
    ./2.7.8/bin/libffi-6.dll
    ./3.2.2/bin/libffi-6.dll

However, we build libffi-8 with ruby 3.2, and it will be installed to the pdk
bin directories in a future commit. So restrict libffi-6 to ruby 2.

configs/components/runtime-pdk.rb

@@ -17,7 +17,7 @@
     pkg.install_file "#{settings[:tools_root]}/bin/libgdbm-4.dll", "#{settings[:ruby_bindir]}/libgdbm-4.dll"
     pkg.install_file "#{settings[:tools_root]}/bin/libgdbm_compat-4.dll", "#{settings[:ruby_bindir]}/libgdbm_compat-4.dll"
     pkg.install_file "#{settings[:tools_root]}/bin/libiconv-2.dll", "#{settings[:ruby_bindir]}/libiconv-2.dll"
-    pkg.install_file "#{settings[:tools_root]}/bin/libffi-6.dll", "#{settings[:ruby_bindir]}/libffi-6.dll"
+    pkg.install_file "#{settings[:tools_root]}/bin/libffi-6.dll", "#{settings[:ruby_bindir]}/libffi-6.dll" if settings[:ruby_version].start_with?('2')
 
     # Copy the DLLs into additional ruby install bindirs as well.
     if settings.has_key?(:additional_rubies)
@@ -26,7 +26,7 @@
         pkg.install_file "#{settings[:tools_root]}/bin/libgdbm-4.dll", "#{local_settings[:ruby_bindir]}/libgdbm-4.dll"
         pkg.install_file "#{settings[:tools_root]}/bin/libgdbm_compat-4.dll", "#{local_settings[:ruby_bindir]}/libgdbm_compat-4.dll"
         pkg.install_file "#{settings[:tools_root]}/bin/libiconv-2.dll", "#{local_settings[:ruby_bindir]}/libiconv-2.dll"
-        pkg.install_file "#{settings[:tools_root]}/bin/libffi-6.dll", "#{local_settings[:ruby_bindir]}/libffi-6.dll"
+        pkg.install_file "#{settings[:tools_root]}/bin/libffi-6.dll", "#{local_settings[:ruby_bindir]}/libffi-6.dll" if rubyver.start_with?('2')
       end
     end