Fix label `x` button showing for unauthorized users

What does this MR do?

This MR hides the sidebar labels x for unauthorized users.

The x button on sidebar labels incorrectly shows even for unauthorized users. Security-wise, there is no issue since when unauthorized users click the x the backend authorization checks prevent the label from being removed. However, this MR fixes this UX inconsistency.

There is no changelog since this fixes a bug in the recently merged feature MR !42703 (merged)

Screenshots

before	after

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

Related to #216881 (closed)