Seems that something broken near Selenium: https://zuul.opendev.org/t/openstack/build/2955e4ff96a74ebeba578f9be64675bd

Selenium and integration jobs fails at start with the same error:

  File "/home/zuul/src/opendev.org/openstack/horizon/.tox/venv/lib/python3.8/site-packages/selenium/webdriver/firefox/webdriver.py", line 138, in __init__
    capabilities = dict(capabilities)
TypeError: 'int' object is not iterable