Use implicit instead of explicit wait

The wait that was added previously is actually needed in a number of tests, so I addressed that by utilizing an implicit wait for the element that we need to assert on. Also, it looked like the previous wait might not actually have been doing what was needed, as it was waiting for an element that is present on every page.

Note that I am seeing a weird failure locally with 4 of these tests, but it isn't showing up on CI. I'd be interested to hear if anyone reviewing this also sees failures unrelated to the waits.