fix(servicecatalog): avoid asset hash change for latest version in Pr…

[1001R]

Issue #24561

Closes #24561.

Reason for this change

When you use ProductStackHistory to handle the previous versions of your product and add a new version, the most recent version (prior to adding the new one) is altered because the asset hash calculated for the product template changes. This occurs because the asset hash for the current version and the historic versions is calculated differently.

Description of changes

I modified the code to ensure that the asset hash for a product template is calculated consistently, whether it comes directly from a ProductStack instance (as it does in the current version) or is retrieved from a snapshot. Previously, for the current version, the code generated the template in memory and hashed the string before saving the template to disk. I reversed this process, now saving the template to disk first and then applying FileSystem.fingerprint to the file—this matches the method used for snapshot versions.

This approach ensures that the asset hashes of historical versions of existing products based on ProductStack remain unchanged, since the code changes only impact the current version.

Describe any new or updated permissions being added

No additional permissions have been introduced, and none of the current ones have been modified.

Description of how you validated changes

I've added a unit test to cover this particular scenario.

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[aws-cdk-automation]

This PR cannot be merged because it has conflicts. Please resolve them. The PR will be considered stale and closed if it remains in an unmergeable state.

[aws-cdk-automation]

This PR cannot be merged because it has conflicts. Please resolve them. The PR will be considered stale and closed if it remains in an unmergeable state.