chore(spec2cdk): remove accidentally added temporary schema (#32465)

### Issue # (if applicable)

N/A

### Reason for this change

Accidentally added the temporary schema in
https://github.com/aws/aws-cdk/pull/32204/files#diff-e0a6c532aa72e71d2fbedefa7286b214a0c0c39251595a11d84f415004d3d1ba.
Should rely on the official CFN schema as it will contain the most
up-to-date information.

### Description of changes

Remove the temporary schema file.

### Description of how you validated changes

N/A

### Checklist
- [ ] My code adheres to the [CONTRIBUTING
GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and
[DESIGN
GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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