TestRequire#test_loading_fifo_threading_success: Extend the timeout limit

Author: mame

test/ruby/test_require.rb

@@ -866,7 +866,7 @@ def test_loading_fifo_threading_success
       File.unlink(f.path)
       File.mkfifo(f.path)
 
-      assert_separately(["-", f.path], "#{<<~"begin;"}\n#{<<~"end;"}", timeout: 3)
+      assert_separately(["-", f.path], "#{<<~"begin;"}\n#{<<~"end;"}", timeout: 10)
       begin;
         path = ARGV[0]
         th = Thread.current