Update docutils to 0.19

What does this MR do and why?

Update to use latest docutils version 0.19, released in July 2022: https://docutils.sourceforge.io/RELEASE-NOTES.html. gitlab-markup has already been updated.

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.

Related to #381733 (closed)