Update tools versions

What does this MR do and why?

Updates the markdownlint version in the image from 0.37.0 to 0.38.0. From this thread in #docs-tooling:

These new versions (markdownlint 0.33.0 and markdownlint-cli 0.38.0) introduces two (new) rules for consideration:

• MD055 (table-pipe-style) for catching inconsistent use of leading / trailing pipe characters, which can cause parsing problems
• MD056 (table-column-count) for catching tables with inconsistent numbers of cells in each row

I'm curious about table-pipe-style, but table-column-count feels more like something we'd want to implement soonish.

Regardless of whether or not we merge this update, I should also document how to update our various testing suites, especially if it also requires a follow-up in the gitlab repo. Future Amy will not remember this.

Screenshots, screen recordings, or links to review app

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Configure a local GitLab Docs environment: https://gitlab.com/gitlab-org/gitlab-docs/-/blob/main/doc/setup.md.

Merge request 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 merge request.