Handle Selenium "options" deprecation

[jordan-brough]

Silences this warning while running "bundle exec rspec":

WARN Selenium [DEPRECATION] [:browser_options] :options as a parameter for
driver initialization is deprecated. Use :capabilities with an Array of
value capabilities/options if necessary instead.

[jordan-brough]

@nickcharlton thanks for merging #2124! I've rebased this on latest main to resolve the merge conflicts.

I see you also merged #2064 (cc @pablobm). This PR is another way to avoid the warnings, while still maintaining the perhaps "nicer"(?) api for configuring the options. I don't think there's anything different other than the syntax, so feel free to close this PR if you want to just stick with what's in main now.

[nickcharlton]

I think on balance, I prefer the way this looks and I often find I (and presumably others) copy out the config so if we've got a better option I'm going to go with it!

Thanks!