Readd spec 6 after deleting it to fix Cypress flakage issues

[fzhao99]

Background

As of this PR we deleted spec 6 of our Cypress suite to get around the flakage isssues. We want eventually to add it back.

Action requested

Spec 6 is back in our CI without flaking.

Acceptance Criteria

A run of 5 runs in a row seems like a good start (maybe try to do so on separate branches to speed this up, ie two copies and getting 2 and 3 runs successfully)

[fzhao99]

Writeup for investigation / last working hypothesis is available here for whoever eventually picks up this ticket. Godspeed brave engineer.