[CONTINT-4500] [helm] Add EKS Clusterrole Rule for EKS control plane metrics

[justin-lesko]

What this PR does / why we need it:

This PR adds a clusterrole rule necessary to allow the agent to query the EKS metrics API as described in the official AWS blog post

Which issue this PR fixes

Special notes for your reviewer:

I tested this by deploying the updated chart to my EKS cluster and validated that the datadog-agent clusterrole contains the new rule

Validate the helm chart is using the latest local

❯ helm ls
NAME         	NAMESPACE	REVISION	UPDATED                             	STATUS  	CHART         	APP VERSION
datadog-agent	default  	1       	2025-02-03 15:12:57.193742 -0500 EST	deployed	datadog-3.90.1	7

Validate the last rule is allowing EKS queries

❯ k get clusterrole datadog-agent -o yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    meta.helm.sh/release-name: datadog-agent
    meta.helm.sh/release-namespace: default
  creationTimestamp: "2025-02-03T20:12:58Z"
  labels:
    app.kubernetes.io/instance: datadog-agent
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: datadog-agent
    app.kubernetes.io/version: "7"
    helm.sh/chart: datadog-3.90.1
  name: datadog-agent
  resourceVersion: "1704410"
  uid: e8e54a1b-4b5a-4636-877f-9ff57eecc0c0
rules:
- nonResourceURLs:
  - /metrics
  - /metrics/slis
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes/metrics
  - nodes/spec
  - nodes/proxy
  - nodes/stats
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - endpoints
  verbs:
  - get
- apiGroups:
  - security.openshift.io
  resourceNames:
  - datadog-agent
  - hostaccess
  - privileged
  resources:
  - securitycontextconstraints
  verbs:
  - use
- apiGroups:
  - coordination.k8s.io
  resources:
  - leases
  verbs:
  - get
- apiGroups:
  - metrics.eks.amazonaws.com
  resources:
  - kcm/metrics
  - ksh/metrics
  verbs:
  - get

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• Chart Version bumped
• Documentation has been updated with helm-docs (run: .github/helm-docs.sh)
• CHANGELOG.md has been updated
• Variables are documented in the README.md
• For Datadog Operator chart or value changes update the test baselines (run: make update-test-baselines)

[clamoriniere]

I wasn't sure but this clusterrole is also use for the cluster-check-runner service account https://github.com/DataDog/helm-charts/blob/main/charts/datadog/templates/agent-clusterchecks-rbac.yaml so it should be ok when the check run as cluster check