help request: PDB for fluentd stateful set

### Describe the issue

When creating a fluentd + fluent-bit deployment using fluent-operator, I don't see a way to configure Pod Disruption Budget for the fluentd stateful set.
I can create the manifest manually or by having an umbrella chart, but I would expect it to be possible when defining the fluentd using the operator.

### How did you install fluent operator?

_No response_

### Additional context

_No response_

Start by tracing how the fluentd StatefulSet is generated and where the operator exposes configuration for it. Check the Kubernetes resource definitions and reconciliation path for an existing Pod Disruption Budget pattern. Done means a fluentd definition can configure a PDB and the operator produces the expected manifest.

Written by the indexing model from the issue text.