Redis and Rust version updates

What does this merge request do and why?

This MR updates Redis and Rust versions to match .tool-versions on gitlab-org/gitlab.

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.

changed milestone to %16.6

added Category:GDK Engineering Productivity Quality maintenancedependency typemaintenance labels

assigned to @nao.hashizume

approved this merge request

enabled automatic add to merge train when the pipeline for 3b727252 succeeds

I'm self-approving and merging to unblock potentially affected users.

started a merge train

merged

mentioned in commit 233e8f6a

mentioned in merge request !3439 (closed)

mentioned in issue gitlab-org/ruby/gems/gitlab-glfm-markdown#2 (closed)

mentioned in merge request !4502 (closed)