Merge branch '469594-update-ci-cd-analytics-page-title-to-be-an-h1-and-add-an-h2-per-tab' into 'master' 

Update page headings in the CI/CD analytics pages

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/184282



Merged-by: David Pisek <dpisek@gitlab.com>
Approved-by: Vitali Tatarintev <vtatarintev@gitlab.com>
Approved-by: Sharmad Nachnolkar <snachnolkar@gitlab.com>
Approved-by: David Pisek <dpisek@gitlab.com>
Reviewed-by: Sharmad Nachnolkar <snachnolkar@gitlab.com>
Co-authored-by: Miguel Rincon <mrincon@gitlab.com>