feat(DesignTokens): add 10 scale to theme colors

mentioned in commit 6d72ab05

mentioned in merge request gitlab!140590 (merged)

mentioned in merge request gitlab-docs!4498 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!3675 (merged)

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!249 (merged)

mentioned in merge request status-page!893 (merged)

mentioned in merge request gitlab-org/frontend/playground/accessibility-scanner!21 (merged)