chore(eks): deprecate older versions of EKS (aws#18842)

EKS version support: https://docs.aws.amazon.com/eks/latest/userguide/kubernetes-versions.html

Kubernetes versions: https://endoflife.date/kubernetes


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packages/@aws-cdk/aws-eks/lib/cluster.ts

@@ -772,21 +772,25 @@ export interface ClusterProps extends ClusterOptions {
 export class KubernetesVersion {
  /**
  * Kubernetes version 1.14
+ * @deprecated Use newer version of EKS
  */
  public static readonly V1_14 = KubernetesVersion.of('1.14');
 
  /**
  * Kubernetes version 1.15
+ * @deprecated Use newer version of EKS
  */
  public static readonly V1_15 = KubernetesVersion.of('1.15');
 
  /**
  * Kubernetes version 1.16
+ * @deprecated Use newer version of EKS
  */
  public static readonly V1_16 = KubernetesVersion.of('1.16');
 
  /**
  * Kubernetes version 1.17
+ * @deprecated Use newer version of EKS
  */
  public static readonly V1_17 = KubernetesVersion.of('1.17');