AWS::RedshiftServerless::Namespace missing AdminPasswordSecretArn

### Name of the resource

AWS::RedshiftServerless::Namespace

### Resource name

_No response_

### Description

AWS::RedshiftServerless::Namespace missing AdminPasswordSecretArn

See:
* https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-redshiftserverless-namespace.html
* https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-redshiftserverless-namespace-namespace.html#cfn-redshiftserverless-namespace-namespace-adminpasswordsecretarn

Related:
* https://github.com/aws/aws-cdk/issues/29930

### Other Details

_No response_

Start with the AWS::RedshiftServerless::Namespace resource and compare its coverage with the linked CloudFormation documentation for AdminPasswordSecretArn. Done means the resource supports the documented AdminPasswordSecretArn property; review the related AWS CDK issue for context before making changes.

Written by the indexing model from the issue text.