After upgrading selenium-webdriver to v4.0.3 at https://github.com/thoughtbot/administrate/commit/9e462f7179f47151d1b91aab59291e6884870dab, a new warning has appeared when running the tests:
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.There's not much documentation as to what the options are and how they should be passed here, but this appears to work. It's based on https://chromedriver.chromium.org/capabilities