[ruby] Update Ruby 4.0.2 → 4.0.3

[depfu]

Here is everything you need to know about this upgrade. Please take a good look at what changed and the test results before merging this pull request.

What changed?

Release Notes

4.0.3

Posted by k0kubun on 21 Apr 2026

      <p>Ruby 4.0.3 has been released.</p>

This release only contains ERB 6.0.1.1, which fixes CVE-2026-41316.

If your application calls Marshal.load on untrusted data AND has both erb and activesupport loaded, please update your ERB to 4.0.3.1, 4.0.4.1, 6.0.1.1, 6.0.4 or later. You may use this Ruby 4.0.3 release to do so.

Release Schedule

We intend to release the latest stable Ruby version (currently Ruby 4.0) every two months following the most recent regular release. Ruby 4.0.4 will be released in May, 4.0.5 in July, 4.0.6 in September, and 4.0.7 in November.

If a change arises that significantly affects users, a release may occur earlier than planned, and the subsequent schedule may shift accordingly.

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