Missing 4.0.4 release in changelog

[TWiStErRob]

https://github.com/Shopify/liquid/releases/tag/v4.0.4 exists https://rubygems.org/gems/liquid/versions/4.0.4 exists Default branch latest changelog entry 4.0.3: https://github.com/Shopify/liquid/blob/main/History.md#403--2019-03-12 I think I might've found the missing one, but it says unreleased and therefore the list might be incomplete: https://github.com/Shopify/liquid/blob/4-0-stable/History.md#404--unreleased