### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When attempting to list roles where permission boundaries are attached the response cannot be serialized 

`aws --endpoint-url=http://localhost:4566 iam list-roles --region ap-southeast-2`
```
An error occurred (InternalError) when calling the ListRoles operation (reached max retries: 2): exception while calling iam.ListRoles: Invalid type when serializing AttachedPermissionsBoundary: '<Element 'member' at 0xffff8275ef20>' cannot be parsed to structure.
```

### Expected Behavior

Expect that all roles are listed

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    docker run localstack/localstack

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

* Create an IAM policy
* Create an IAM role which used the policy as a permission boundary
* Attempt to list all roles with `aws --endpoint-url=http://localhost:4566 iam list-roles --region ap-southeast-2`


### Environment

```markdown
- OS: MacOS
- LocalStack: latest
```


### Anything else?

_No response_
"""
        :return: array with Transformers, for s3 api.
        """
        s3 = [
            TransformerUtility.key_value("Name", value_replacement="bucket-name"),
            TransformerUtility.key_value("BucketName"),
            TransformerUtility.key_value("VersionId"),
            TransformerUtility.jsonpath(
                jsonpath="$..Owner.DisplayName",
                value_replacement="<display-name>",
                reference_replacement=False,
            ),
            TransformerUtility.jsonpath(
                jsonpath="$..Owner.ID", value_replacement="<owner-id>", reference_replacement=False
            ),
        ]
        
        s3.extend(TransformerUtility.s3_notifications_transformer())
        return s3
    @s
    def s3_notifications_transformer():