feat(ec2): add i4i instance type (#20134)

https://aws.amazon.com/about-aws/whats-new/2022/04/amazon-ec2-i4i-instances/

----

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Author: robertd

packages/@aws-cdk/aws-ec2/lib/instance-types.ts

@@ -452,6 +452,16 @@ export enum InstanceClass {
    */
   I3EN = 'i3en',
 
+  /**
+   * I/O-optimized instances with local NVME drive powered by Intel Xeon Scalable processors (code named Ice Lake), 4th generation
+   */
+  IO4_INTEL = 'i4i',
+
+  /**
+   * I/O-optimized instances with local NVME drive powered by Intel Xeon Scalable processors (code named Ice Lake), 4th generation
+   */
+  I4I = 'i4i',
+
   /**
    * Storage optimized instances powered by Graviton2 processor, 4th generation
    */