Inconsistency with workshop role name

# Please follow the general issue steps first:

- [x] Bug
- [ ] Enhancement
- [ ] Feature Request

### Bug reports:
The instruction to [verify IAM role](https://serverless-observability.workshop.aws/en/020_prerequisites/workspace/workspaceiam.html#validate-the-iam-role) confusing. Names do not match.

### Enhancement / Feature Requests:

**Please note by far the quickest way to get a new feature is to file a Pull Request.**

Please verify and update the role name to match the output "workshop-role"

We will consider your request but it may be closed if it's something we're not actively planning to work on.