WIP Fix MediawikiSelenium::ConfigurationError in selenium-Wikidata Jenkins job
86513b8 introduced test environment in ci.yml, but did not specify it
in environments.yml. Since test2 environment is not used, replaced it
with test, and changed mediawiki_url accordingly.
Bug: T140097
Change-Id: Ic7ec57b18ea9c0ab1ab8353bfee39856254a75c4