Mark tests requiring dash / Selenium so they can be turned off

[kwinkunks]

The chromium-browser version on Azure at the moment does not have a chromedriver available, and trying to download it throws a 404: https://github.com/equinor/komodo-releases/actions/runs/6885078281/job/18729226670

This should never happen, it seems to be a bug on RedHat's part (?).

AFAIK, there's no other way to get Chrome drivers -- we are following the advice here https://googlechromelabs.github.io/chrome-for-testing/ -- some versions simply do no exist.

But we could mark tests requiring the driver, however, so that if situations like this happen again, we can easily turn off the tests temporarily.

[kwinkunks]

Pressure on this is relieved a bit by making the download more robust in #454