Spec annotation can not be retrieved by the management endpoints (maybe through the openapi spec) and its helpful to use those by a backstage plugin to add backstage-related annotation on it.

Actual:
Have a spec of:
```yaml
id: foo
name: foo
annotations:

• "foo/bar"

GET /management/processes/foo

I looked into org.kie.kogito.process.Process interface and it is missing there as well (2.0.0 snapshot) and also nothing returns it on `BaseProcessInstanceManagementResource`