Increase head node memory limit for RayService sample to avoid OOM (#4089)

Signed-off-by: wei-chenglai <[email protected]>

Author: seanlaii

ray-operator/config/samples/ray-service.sample.yaml

@@ -77,7 +77,7 @@ spec:
             resources:
               limits:
                 cpu: 2
-                memory: 2Gi
+                memory: 5Gi
               requests:
                 cpu: 2
                 memory: 2Gi