aws-redshift-alpha: Triggers [WARNING] aws-cdk-lib.custom_resources.ProviderProps#role is deprecated

### Describe the bug

The property role in aws-cdk-lib.custom_resources.ProviderProps has been officially deprecated. It is scheduled for removal in the next major release of the AWS CDK according to the warning.

Currently, the DatabaseQuery private construct within the aws-redshift-alpha module is still utilizing this deprecated property, which triggers a warning during synthesis.

### Regression Issue

- [ ] Select this option if this issue appears to be a regression.

### Last Known Working CDK Library Version

_No response_

### Expected Behavior

No deprecation warnings.

### Current Behavior

Deprecation warnings

### Reproduction Steps

Create a User using the `aws_redshift_alpha` library.
https://docs.aws.amazon.com/cdk/api/v2/python/aws_cdk.aws_redshift_alpha/README.html#creating-users

```
User(self, "User",
cluster=cluster,
database_name="databaseName"
)
```

### Possible Solution

Update [database-query.ts#L65](https://github.com/aws/aws-cdk/blob/aa51aa2f5e6528cec6f139b772a694a6f2c509b1/packages/@aws-cdk/aws-redshift-alpha/lib/private/database-query.ts#L65) to use the new properties.

### Additional Information/Context

_No response_

### AWS CDK Library version (aws-cdk-lib)

2.238.0

### AWS CDK CLI version

2.1021.0

### Node.js Version

v22.15.0

### OS

macOs 26.2

### Language

Python

### Language Version

_No response_

### Other information

_No response_

Start at packages/@aws-cdk/aws-redshift-alpha/lib/private/database-query.ts#L65 and inspect how DatabaseQuery constructs ProviderProps. Reproduce the warning with the User example from the issue, then update the usage to the new properties and verify synthesis completes without deprecation warnings.

Written by the indexing model from the issue text.