Don't use test-queue to run tests on JRuby or Windows because they …

…don't support `fork`

.github/workflows/test.yml

@@ -50,8 +50,6 @@ jobs:
           bundler-cache: true
       - name: test
         run: bundle exec rake test
-        env:
-          ERROR_ON_TEST_FAILURE: "false"
       - name: internal_investigation
         run: bundle exec rake internal_investigation
 

Rakefile

@@ -19,11 +19,20 @@ require 'rubocop/rake_task'
 require 'rake/testtask'
 require_relative 'lib/rubocop/cop/generator'
 
-desc 'Run tests'
-task :test do
-  error_on_failure = ENV.fetch('ERROR_ON_TEST_FAILURE', 'true') != 'false'
+# JRuby and Windows don't support fork, so we can't use minitest-queue.
+if RUBY_ENGINE == 'jruby' || RuboCop::Platform.windows?
+  Rake::TestTask.new do |t|
+    t.libs << 'test'
+    t.libs << 'lib'
+    t.test_files = FileList['test/**/*_test.rb']
+  end
+else
+  desc 'Run tests'
+  task :test do
+    error_on_failure = ENV.fetch('ERROR_ON_TEST_FAILURE', 'true') != 'false'
 
-  system("bundle exec minitest-queue #{Dir.glob('test/**/*_test.rb').shelljoin}", exception: error_on_failure)
+    system("bundle exec minitest-queue #{Dir.glob('test/**/*_test.rb').shelljoin}", exception: error_on_failure)
+  end
 end
 
 desc 'Run RuboCop over itself'