Update capybara for Ruby 3 support

Our functional test suite fails to invoke with Ruby 3 and the current library version 3.35.3: https://gitlab.com/gitlab-org/gitlab/-/jobs/1444854251#L71

The latest version is 3.36.0 which may or may not fix this: https://github.com/teamcapybara/capybara/blob/master/History.md#version-3360