Use 1Password CLI to pull OTP for GitHub OAuth

Use 1Password CLI to pull OTP for GitHub OAuth

Requires Gitlab-QA MR: gitlab-qa!282 (merged)

Closes: https://gitlab.com/gitlab-org/quality/nightly/issues/121

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