Prevent unnecessary namespace listing

[JBBianchi]

What would you like to be added:
Avoid listing namespaces when they are not required, namely in a workflow details view.

Why is this needed:
In the workflow details view, when listing the instances of a workflow, the list component currently retrieves the list of namespaces by default. This is typically used to populate a dropdown for filtering entities by namespace.

However, in cases where the namespace is predefined by the workflow definition and fixed, the namespace dropdown is not displayed. In such situations, fetching the list of namespaces is unnecessary and could be avoided to improve efficiency.