PR-20822: [fix][broker] Avoid infinite bundle unloading

[streamnativebot]

url: apache#20822

Motivation

When unload happens, the bundle ownership assignment logic doesn't know the previous unloaded broker. It might assign the bundle to the same broker. In this case, it might cause an infinite bundle unloading loop.

Modifications

• Avoid assigning bundle to the previous unloaded broker

Verifying this change

See the ModularLoadManagerImplTest#testAvoidAssignBundleToPreviousUnloadedBroker unit test.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete