(@aws-cdk/aws-dynamodb): DynamoDb Replication: Cannot exceed quota for PoliciesPerRole: 10

```
Cannot exceed quota for PoliciesPerRole: 10 (Service: AmazonIdentityManagement; Status Code: 409; Error Code: LimitExceeded; Request ID: 3bd4add0-36e4-44ad-8e98-947977c0a638; Proxy: null)
```

Starting from version 1.92.0 I can't deploy my global tables.

https://github.com/aws/aws-cdk/pull/13300 seems like this is the change that introduced this bug for me.

### Reproduction Steps

### What did you expect to happen?

### What actually happened?

### Environment

- **CDK CLI Version : 1.92.0**
- **Framework Version: 1.92.0**
- **Node.js Version: v12.6.0**
- **OS : arch linux**
- **Language (Version): TypeScript**

### Other

---

This is :bug: Bug Report

Start by reviewing pull request #13300 and comparing the global-table deployment behavior between versions 1.91.0 and 1.92.0. Reproduce the deployment with the reported PoliciesPerRole quota error, then verify that the affected DynamoDB replication path deploys without exceeding the IAM policy quota.

Written by the indexing model from the issue text.