Update rails-html-sanitizer to v1.4.4

What does this MR do and why?

This addresses some CVEs.

Diff: https://my.diffend.io/gems/rails-html-sanitizer/1.4.3/1.4.4

Changes: https://github.com/rails/rails-html-sanitizer/blob/master/CHANGELOG.md

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.