Do not allow removing the last admin role of a project

[rdimitrov]

Summary

The following PR adds a check in case the user is removing the last admin role of a project.

Change Type

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• 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

Outline how the changes were tested, including steps to reproduce and any relevant configurations.
Attach screenshots if helpful.

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.

[coveralls]

coverage: 52.49% (+0.02%) from 52.466%
when pulling 3b055ca on remove-admin-check
into cae4b26 on main.

[coveralls]

coverage: 52.481% (+0.02%) from 52.466%
when pulling 8f4dee0 on remove-admin-check
into cae4b26 on main.