lang/ruby40: Update to 4.0.3
Changes: https://github.com/ruby/ruby/releases
https://github.com/ruby/ruby/blob/master/NEWS.md https://www.ruby-lang.org/en/news/2026/04/21/ruby-4-0-3-released/
(cherry picked from commit a5a7f09dcf62b516c9df70818b2346268cb1dcba)