Support `managedBy` field on `SparkApplication` for integration with MultiKueue

[everpeace]

What feature you would like to be added?

The support for the managedBy field which can delegate reconciliation from built-in controller, to a custom one.

The semantics of the field are:　whenever the value is set, and it does not point to the built-in operator, then skip reconciliation

• the field is immutable
• the field is not defaulted

Why is this needed?

Integration with MultiKueue (multi-cluster Kueue):

• simpler installation (just follow the standard installation path), otherwise only installation of SparkApplication CRDs is required
• support for mixed setup in one cluster - some SparkApplication could be run by MultiKueue and some by the default operator

The managedBy field is already adopted by:

• Job API managed-by mechanism kubernetes/enhancements#4368 (beta in 1.32)
• Introduce managedBy field kubernetes-sigs/jobset#440 (released in 0.6)
• Add support for the managedBy field mpi-operator#646 (released in 0.6)
• Add support for the managedBy field trainer#2193 (released in 1.9)
• [Feature] Support managedBy for integration with MultiKueue ray-project/kuberay#2544 (released in 1.3.0)

Describe the solution you would like

Introduce spec.managedBy field in SparkApplication

Describe alternatives you have considered

No response

Additional context

as suggested in kubernetes-sigs/kueue#7268 (comment)

Love this feature?

Give it a 👍 We prioritize the features with most 👍