[v3-3-test] Make the CI unit test timeout fire before the job timeout…

[potiuk]

… does (#72259)

• Make the CI unit test timeout fire before the job timeout does

The test timeout exists so that a hanging test group is stopped while the job still has time to dump the container logs and upload them as artifacts. It never got that chance. The alarm is armed in the last step of the job, but the job budget starts at the first one, and checking out the repo, pulling the CI image and running the migration tests routinely take twenty minutes or more before any test runs. A fixed sixty minute test timeout could therefore only fire in a job GitHub had already cancelled, so every hang surfaced as a bare job timeout with no logs to explain it.

• Print the CI test budget in minutes and seconds

The line reported the budget left in seconds next to a job timeout in minutes, so anyone reading it had to convert one to compare them. (cherry picked from commit 14397bc)

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