[rubygems/rubygems] Tweak to spec setup so that rspec instead of our bin/rspec binstub still works

ruby/rubygems@24e6699316

Author: deivid-rodriguez

spec/bundler/support/rubygems_ext.rb

@@ -28,6 +28,9 @@ def gem_require(gem_name, entrypoint)
     end
 
     def test_setup
+      # Install test dependencies unless parallel-rspec is being used, since in that case they should be setup already
+      install_test_deps unless ENV["RSPEC_FORMATTER_OUTPUT_ID"]
+
       setup_test_paths
 
       require "fileutils"