tests/selenium/selenium.sh file and selenium NPM script in package.json should not be needed any more.
As far as I know, Selenium tests are using selenium-test NPM script.
Change 650226 had a related patch set uploaded (by Zfilipin; owner: Zfilipin):
[mediawiki/core@master] WIP Selenium: Delete tests/selenium/selenium.sh
Change 650226 merged by jenkins-bot:
[mediawiki/core@master] Selenium: Delete tests/selenium/selenium.sh