tool validate-redirects is missing in rari

[caugner]

What information was incorrect, unhelpful, or incomplete?

We run tool validate-redirects in mdn/content and mdn/translated-content to validate the redirects files, but these checks are now failing, because rari doesn't seem to have implemented this subcommand.

What did you expect to see?

The command should exist and validate the redirects files.

Do you have any supporting links, references, or citations?

See: https://github.com/mdn/content/actions/runs/12987566319/job/36216729821?pr=37343#step:6:1

Do you have anything more you want to share?

No response

[fiji-flo]

fixed in #102