hides CLI profile list label flag

[ChrisJBurns]

Summary

At the moment, there are some labels that minder uses internally, but we don't expose label managements to the end user. Therefore the --label flag in profile list is confusing. We should make the flag hidden. We should use cobra's hidden attribute to hide the flag.

Fixes #3300

Change Type

Mark the type of change your PR introduces:

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

Run make test, there are failures but not entirely sure they are related to the change made in the PR, and may be due to a local setup issue. I could not see any test change needed to be made, it is my first PR so I welcome any correction to my understanding.

When building the CLI, the label flag does not appear anymore in the help information

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

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