[RFC]: Add dependencies field in StormService

🚀 Feature Description and Motivation

I deploy vLLM+LMCache+Mooncake with StormService in my production K8S like this:

apiVersion: orchestration.aibrix.ai/v1alpha1
kind: StormService
metadata:
  name: vllm-lmcache-mooncake
spec:
  replicas: 1
  updateStrategy:
    type: InPlaceUpdate
  stateful: true
  selector:
    matchLabels:
      app: vllm-lmcache-mooncake
  template:
    metadata:
      labels:
        app: vllm-lmcache-mooncake
    spec:
      roles:
        - name: mooncake-master
          replicas: 1
          stateful: true

        - name: mooncake-store
          replicas: 1
          stateful: true

       - name: vllm
          replicas: 1
          dependencies:  # new field
            - "mooncake-master"
          stateful: true

the vllm pod dependency on the mooncake-master pod, it needs mooncake-master pod starts firstly.

I found RBG https://github.com/sgl-project/rbg/blob/main/keps/74-mooncake-integration/README.md#deploy-standalone-inference-service-with-mooncake has the dependencies field.

it's best to add dependencies field at StormService.

Use Case

Deploy vLLM+Mooncake Store in K8S.

Proposed Solution

No response