[AWS:Cognito] - [BUG] - Cannot create cfn user pool with only email MFA enabled

### Name of the resource

AWS::Cognito::UserPool

### Resource Name

AWS:COGNITO:USERPOOL

### Issue Description

User is trying to create a Cognito user pool using the L1 construct and ONLY email MFA enabled leads to an error in CloudFormation.

This DOES work if I create the same user pool without any MFA enabled and then go to the AWS console and update it manually to have email only MFA.

### Expected Behavior

CloudFormation is able to create the requested resource without issues.

### Observed Behavior

Error received -
```
Resource handler returned message: "SMS configuration and Auto verification for phone_number are required when MFA is required/optional (Service: CognitoIdentityProvider, Status Code: 400, Request ID: ..., HandlerErrorCode: InvalidRequest)
```

### Test Cases

Here is an example of a stack that yields the error in CloudFormation
```ts
import * as cognito from 'aws-cdk-lib/aws-cognito';
import { App, Stack, StackProps } from 'aws-cdk-lib/core';

export class AuthStack extends Stack {
constructor(scope: App, id: string, props: StackProps) {
super(scope, id, props);

const userPool = new cognito.CfnUserPool(this, 'UserPool', {
userPoolName: 'UserPool123',
adminCreateUserConfig: {
allowAdminCreateUserOnly: true,
unusedAccountValidityDays: 1,
},
usernameAttributes: ['email'],
usernameConfiguration: {
caseSensitive: false,
},
enabledMfas: ['EMAIL_OTP'],
mfaConfiguration: 'OPTIONAL',
});
}
}

```
user also tried giving `EmailConfiguration` in the [docs](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cognito-userpool.html#aws-resource-cognito-userpool-properties) but it still yields the same error

### Other Details

Origiinal issue reported in CDK -https://github.com/aws/aws-cdk/issues/32615
Previous issue ( not similar but linked) - https://github.com/aws/aws-cdk/issues/11478

Start with the TypeScript CfnUserPool example in the issue and reproduce the CloudFormation error using enabledMfas: ['EMAIL_OTP'] and mfaConfiguration: 'OPTIONAL'. Compare the requested properties with the linked CloudFormation Cognito UserPool documentation and CDK issue 32615. Done means the same stack creates successfully with email-only MFA without requiring SMS configuration or phone auto-verification.

Written by the indexing model from the issue text.