revert: route53 CrossAccountZoneDelegationRecord fails at deployment time with imported delegatedZone (#30440)" (#30606)

This reverts commit a3d9b10.

### Issue # (if applicable)

Closes #30600.

### Reason for this change

Reverting #30440 so that `cdk synth` succeed when using imported `delegatedZone`

### Description of changes

Removed the `throw new Error()`

### Description of how you validated changes



### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

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

Author: samson-keung

packages/aws-cdk-lib/aws-route53/README.md

@@ -313,7 +313,7 @@ const delegationRole = iam.Role.fromRoleArn(this, 'DelegationRole', delegationRo
 
 // create the record
 new route53.CrossAccountZoneDelegationRecord(this, 'delegate', {
-  delegatedZone: subZone, // Note that an imported HostedZone is not supported as Name Servers info will not be available
+  delegatedZone: subZone,
   parentHostedZoneName: 'someexample.com', // or you can use parentHostedZoneId
   delegationRole,
 });

packages/aws-cdk-lib/aws-route53/lib/record-set.ts

@@ -929,10 +929,6 @@ export class CrossAccountZoneDelegationRecord extends Construct {
       throw Error('Only one of parentHostedZoneName and parentHostedZoneId is supported');
     }
 
-    if (!props.delegatedZone.hostedZoneNameServers) {
-      throw Error(`Not able to retrieve Name Servers for ${props.delegatedZone.zoneName} due to it being imported.`);
-    }
-
     const provider = CrossAccountZoneDelegationProvider.getOrCreateProvider(this, CROSS_ACCOUNT_ZONE_DELEGATION_RESOURCE_TYPE);
 
     const role = iam.Role.fromRoleArn(this, 'cross-account-zone-delegation-handler-role', provider.roleArn);

packages/aws-cdk-lib/aws-route53/test/record-set.test.ts

@@ -893,27 +893,6 @@ describe('record set', () => {
     });
   });
 
-  test('CrossAccountZoneDelegationRecord should throw if delegatedZone is imported', () => {
-    // GIVEN
-    const stack = new Stack();
-    const parentZone = new route53.PublicHostedZone(stack, 'ParentHostedZone', {
-      zoneName: 'myzone.com',
-    });
-
-    // WHEN
-    const childZone = route53.PublicHostedZone.fromPublicHostedZoneAttributes(stack, 'ChildHostedZone', {
-      hostedZoneId: 'fake-id',
-      zoneName: 'fake-name',
-    });
-
-    //THEN
-    expect(() => new route53.CrossAccountZoneDelegationRecord(stack, 'Delegation', {
-      delegatedZone: childZone,
-      parentHostedZoneId: parentZone.hostedZoneId,
-      delegationRole: parentZone.crossAccountZoneDelegationRole!,
-    })).toThrow(/Not able to retrieve Name Servers for fake-name due to it being imported./);
-  });
-
   testDeprecated('Cross account zone delegation record with parentHostedZoneName', () => {
     // GIVEN
     const stack = new Stack();