E2E: Enable login with 2FA specs to run on live environments

What does this MR do and why?

Update login with 2FA specs to run on live environments

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

From the qa directory, run:

GITLAB_QA_USER_AGENT=<GITLAB_QA_USER_AGENT> GITLAB_ADMIN_USERNAME="gitlab-qa-bot" GITLAB_ADMIN_PASSWORD="<GITLAB_ADMIN_PASSWORD>" GITLAB_QA_ADMIN_ACCESS_TOKEN="<GITLAB_QA_ADMIN_ACCESS_TOKEN>" GITLAB_USERNAME=gitlab-qa GITLAB_PASSWORD="<GITLAB_PASSWORD>" GITLAB_QA_ACCESS_TOKEN="<GITLAB_QA_ACCESS_TOKEN>" QA_DEBUG=true bundle exec bin/qa Test::Instance::All https://staging.gitlab.com qa/specs/features/browser_ui/1_manage/login/log_in_with_2fa_spec.rb

All secrets are in 1P GitLab-QA vault

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.