Dropped roles can still be assigned to collaborators

[ghislaineguerin]

Description

After creating a role on the server and subsequently dropping it, I was still able to assign the dropped role to a collaborator. Upon doing so, the app became unresponsive and displayed the following error:

[-30193] OperationalError: connection failed: FATAL: password authentication failed for user "test"

Expected behavior

Users should not be able to assign roles that have already been dropped from the server. The system should validate the role's existence before allowing it to be assigned to collaborators.

To Reproduce

• Drop the role from the server.
• Attempt to assign the dropped role to a collaborator.
• The app becomes unresponsive and displays the above error.