Support stack-level tags for AWS::IoT::Policy resource type

### Name of the resource

AWS::IoT::Policy

### Resource name

_No response_

### Description

Stack-level tags are not propagated to the AWS::IoT::Policy resource type, despite supporting the Tags property.

### Other Details

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-iot-policy-tag.html

Start with the linked AWS IoT Policy tagging documentation and then inspect how this repository tracks stack-level tag support for resource types; no file, entry point, or test is named. Done means stack-level tags are propagated to AWS::IoT::Policy, which supports the Tags property.

Written by the indexing model from the issue text.