Churn with `aws_iam_role.this`

### Describe the Bug

There is a permanent name change with `aws_iam_role.this` which is causing the resource to be recreated on every apply.

This is causing further issues with KMS permissions in the lambda function being revoked, including permissions to the default KMS key.

See https://github.com/serverless/examples/issues/279 for context regarding KMS key

### Expected Behavior

IAM role should not be constantly recreated.

### Steps to Reproduce

Apply module, apply again.

### Screenshots

_No response_

### Environment

_No response_

### Additional Context

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Start by applying the module twice and inspecting the aws_iam_role.this resource between runs; the issue identifies the permanent name change as the entry point. Done means the second apply no longer recreates the IAM role and the Lambda function retains its KMS permissions.

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