[Bug] Fix health probes to use custom ports from rayStartParams

[MiniSho]

What type of PR is this?
Bug fix

What this PR does / why we need it:
This PR fixes an issue where the liveness and readiness probes in Ray pods were hardcoded to use default ports, ignoring custom port configurations specified in rayStartParams. This caused probe failures when users customized ports like dashboard-port or dashboard-agent-listen-port.

Which issue(s) this PR fixes:
Fixes health probe failures when custom ports are configured in rayStartParams.

Special notes for your reviewer:
The fix extracts port values from rayStartParams with fallback to default values, ensuring probes use the correct ports that Ray processes are actually listening on.

[MiniSho]

@kevin85421 PTAL~

[Future-Outlier]

Can you help me add an integration test to prove it?
And also provide a screenshot and a yaml file to show me how you test it, thank you!

[win5923]

I tested with the following YAML, and it worked well. Thanks!

apiVersion: ray.io/v1
kind: RayCluster
metadata:
  name: raycluster-kuberay
spec:
  rayVersion: '2.46.0'
  headGroupSpec:
    rayStartParams:
      dashboard-port: "8266"
      dashboard-agent-listen-port: "8267"
    template:
      spec:
        containers:
        - name: ray-head
          image: rayproject/ray:2.46.0
          resources:
            limits:
              cpu: 1
              memory: 2G
            requests:
              cpu: 1
              memory: 2G
          ports:
          - containerPort: 6379
            name: gcs-server
          - containerPort: 8266 # Ray dashboard
            name: dashboard
          - containerPort: 10001
            name: client

[win5923]

In v1.5.0 we might modify the liveness and readiness probes when we get rid of wget, so I’m not sure if this PR is still needed.

#3837