Ensure we check for correct status code when testing cli download links

[richard-cox]

Summary

Fixes #

Occurred changes and/or fixed issues

• In v2.9-head the links the UI uses to provide the download cli links will soon be updated to 2.9.2
• Those links though are dead and won't exist until after 2.9.2 is released
• In the short term check that they're dead
• Note 1 - Once they're fixed we'll know, as the e2e tests will start failing
• Note 2 - This will fail until v2.9-head changes merge and build happens. We can force merge if needs be

Checklist

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