Add validation tests for v1beta2 TopologyAssignment #7639
Description
What would you like to be cleaned:
I'd like to have an integration test for the validation rules in the v1beta2 TopologyAssignment (introduced in #7544).
Why is this needed:
The validation rules are specified via Kubebuilder annotations. While the existing automation does some checking of those, I'm not 100% certain if they behave as intended. It'd be nice to have tests for this.