k6 cloud --quiet exits immediately after the test run starts

[na--]

This check: https://github.com/loadimpact/k6/blob/4c7c4bf135a8b68a77549484d2a627fee4128570/cmd/cloud.go#L191-L193

causes --quiet to exit the k6 cloud process prematurely. This may sometimes be useful, but we have another option that is specifically meant for that, k6 cloud --exit-on-running, so we should fix this.

[qcastel]

To give a bit more context on why I was trying to use this option and hit that bug:

When you run K6 cloud from a CI, the progression bar is spamming the CI log. As we are limited on the number of logs we can do in CI, I was interested to avoid having those progressing logs.