[CE] Retry the first login page validation

What does this MR do?

It can take longer that 60 seconds for the server to be ready to respond. Retry the login page validation twice (i.e., 3 attempts to validate the login page)

EE MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13941

Closes https://gitlab.com/gitlab-org/quality/nightly/issues/103

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content