exclude TestRDocRubyGemsHook at job of ruby-core

Author: mterada1228

.github/workflows/ruby-core.yml

@@ -55,5 +55,5 @@ jobs:
           ruby tool/sync_default_gems.rb rdoc
         working-directory: ruby/ruby
       - name: Test RDoc
-        run: make -j2 -s test-all TESTS="rdoc --no-retry"
+        run: make -j2 -s test-all TESTS="rdoc --no-retry --exclude test_rdoc_rubygems_hook.rb"
         working-directory: ruby/ruby

test/rdoc/test_rdoc_rubygems_hook.rb

@@ -5,7 +5,7 @@
 require_relative '../../lib/rubygems_plugin'
 require 'test/unit'
 
-class TestRDocRubygemsHook < Test::Unit::TestCase
+class TestRDocRubyGemsHook < Test::Unit::TestCase
   def setup
     @a = Gem::Specification.new do |s|
       s.platform    = Gem::Platform::RUBY