[ruby/psych] Comment out the code used to expand the file list [ci skip]

https://github.com/ruby/psych/commit/715f3bfad0

ext/psych/psych.gemspec

@@ -23,9 +23,9 @@ DESCRIPTION
 
   # for ruby core repository.
   # It was generated by
-  `git ls-files -z`.split("\x0").reject { |f|
-    f.match(%r{^\.git|^(test|spec|features|bin|tool)/|^[A-Z]\w+file$|/extlibs$|\.(gemspec|java)$|jar})
-  }
+  # `git ls-files -z`.split("\x0").reject { |f|
+  #   f.match(%r{^\.git|^(test|spec|features|bin|tool)/|^[A-Z]\w+file$|/extlibs$|\.(gemspec|java)$|jar})
+  # }
   s.files = [
     "CONTRIBUTING.md", "LICENSE", "README.md", "ext/psych/depend",
     "ext/psych/extconf.rb", "ext/psych/psych.c", "ext/psych/psych.h",