chore: rollback GenericSSMParameterImage deprecation (#16798)

This class was deprecated because it should not have been used directly:

- It is used more as a base class for other images
- It should be accessed through factory functions on `MachineImage`.
- It has an uppercased acronym `SSM`, which should have been spelled as
  `Ssm`.

The deprecated API stripper does the wrong thing when a base class is
deprecated however, and leaves `WindowsImage` in a broken state. See
aws/jsii#3025

Temporarily rolling this back until we can fix jsii.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

(cherry picked from commit 5dfc507)

packages/@aws-cdk/aws-ec2/lib/machine-image.ts

@@ -149,10 +149,12 @@ export interface MachineImageConfig {
  * on the instance if you are using this image.
  *
  * The AMI ID is selected using the values published to the SSM parameter store.
- *
- * @deprecated Use `MachineImage.fromSsmParameter()` instead
  */
 export class GenericSSMParameterImage implements IMachineImage {
+  // FIXME: this class ought to be `@deprecated` and removed from v2, but that
+  // is causing build failure right now. Ref: https://github.com/aws/jsii/issues/3025
+  // @-deprecated Use `MachineImage.fromSsmParameter()` instead
+
   /**
    * Name of the SSM parameter we're looking up
    */
@@ -679,4 +681,4 @@ function lookupImage(scope: Construct, cachedInContext: boolean | undefined, par
   return cachedInContext
     ? ssm.StringParameter.valueFromLookup(scope, parameterName)
     : ssm.StringParameter.valueForTypedStringParameter(scope, parameterName, ssm.ParameterType.AWS_EC2_IMAGE_ID);
-}
+}