[Chore] init map with size

[fscnick]

Why are these changes needed?

It would be better to initialize a map with the size if it could be estimated.

For rayClusterLabels, there are two additional assignments besides rayService.Labels.

kuberay/ray-operator/controllers/ray/rayservice_controller.go

Lines 774 to 779 in f123a44

	rayClusterLabel := make(map[string]string)
	for k, v := range rayService.Labels {
	rayClusterLabel[k] = v
	}
	rayClusterLabel[utils.RayOriginatedFromCRNameLabelKey] = rayService.Name
	rayClusterLabel[utils.RayOriginatedFromCRDLabelKey] = utils.RayOriginatedFromCRDLabelValue(utils.RayServiceCRD)

For rayClusterAnnotations, there are three additional assignments besides rayService.Annotations.

kuberay/ray-operator/controllers/ray/rayservice_controller.go

Lines 781 to 792 in f123a44

	rayClusterAnnotations := make(map[string]string)
	for k, v := range rayService.Annotations {
	rayClusterAnnotations[k] = v
	}
	rayClusterAnnotations[utils.HashWithoutReplicasAndWorkersToDeleteKey], err = generateHashWithoutReplicasAndWorkersToDelete(rayService.Spec.RayClusterSpec)
	if err != nil {
	return nil, err
	}
	rayClusterAnnotations[utils.NumWorkerGroupsKey] = strconv.Itoa(len(rayService.Spec.RayClusterSpec.WorkerGroupSpecs))
	// set the KubeRay version used to create the RayCluster
	rayClusterAnnotations[utils.KubeRayVersion] = utils.KUBERAY_VERSION

Related issue number

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

[cchung100m]

LGTM, thanks to @fscnick 😄