Fix inconsistent test failures

[joshtrichards]

Is it just a timing matter or something more?

Let's figure it out and determine what we can do to make them more reliable.

[joshtrichards]

Some historical context from the last pass:

• Adjust nextcloud tests to avoid flakiness docker-library/official-images#11801
• Be more patient with Nextcloud setups docker-library/official-images#6252