Remove utility classes now present in gitlab-ui

What does this MR do?

This MR removes two CSS utility classes now that they are present in the gitlab-ui CSS

These utility classes have been added in this MR: !35584 (merged)

And this MR added them to gitlab-ui: gitlab-ui!1542 (merged)

Now that the version of gitlab-ui that contains those utility classes in merged in gitlab codebase we can remove them

Screenshots

No visual changes ( as it should be! )

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team

Part of #216962 (closed)