Rethink `SpinAppExecutor` deployment config options

[calebschoepp]

The createDeployment field is redundant. We can determine whether the deployment should be created based on whether deploymentConfig is defined or not.

[endocrimes]

lazy q: do we have any required deploymentConfig fields today? - I thought everything had defaults

[calebschoepp]

Looks like there is a required field

type ExecutorDeploymentConfig struct {
	// RuntimeClassName is the runtime class name that should be used by pods created
	// as part of a deployment.
	RuntimeClassName string `json:"runtimeClassName"`
}

[endocrimes]

We talked about this offline and settled on redesigning the fields over blanket removing things, tagging with api-next and self-assigning for design