CloudFormation Git sync - Nested stacks

### Name of the resource

AWS::CloudFormation::Stack

### Resource Name

_No response_

### Issue Description

We have enabled CloudFormation Git sync on our root template.

Layout
- src
|- root.yaml
| - ecs.yaml
- deploy.yaml

Ofcourse there are more files in this repo but that is not important for this example

The ecs.yaml is included via nested stack from root.yaml

### Expected Behavior

When ecs.yml changes and is pushed to the monitored branch I expect that this file will be processed by Cloudformation to change resources.

### Observed Behavior

- make a change in ecs.yaml
- Push it to the branch
- See Cloudformation start the update process
- See that the ecs stack is also performing the "update"
- Looking on the "template" tab for ecs, I see an old version of the ecs template
- No resources in ecs.yaml or underlying stacks get update.

### Test Cases

- Configure git sync on an existing repo with nesting stacks
- Update a nested stack template file
- Push to branch
- See nothing changing.

### Other Details

This was on already existing stack

Start with src/root.yaml, src/ecs.yaml, and deploy.yaml to verify how the nested stack is referenced. Reproduce the change on the monitored branch through CloudFormation Git sync, then confirm that the nested template and its underlying resources update to match ecs.yaml.

Written by the indexing model from the issue text.