Supporting custom resources that don't have a podSpecTemplate

[drmorr0]

Discussed in #135

^{Originally posted by shravan-achar September 18, 2024}
Some custom resources such as Spark Applications (https://github.com/kubeflow/spark-operator/blob/master/config/crd/bases/sparkoperator.k8s.io_sparkapplications.yaml) which do create pods but do not expose a full podSpec template in its custom resource definition.

Potentially, the tracer can watch pods and track ownership based on labels/annotations instead of the owner reference field.

This seems like a bug that we should fix.

[drmorr0]

#143 is the first step towards supporting this; we no longer require the podSpecTemplatePath in the tracer config. However I think this may still not completely work in the simulated environment; I will need to do some testing and see.