chore: manifest.json should have stable json

[mutahhir]

Description

Ensure that the manifest.json file has stable output. Removes instances where test snapshots fail when no content has changed, but JSON.stringify shuffles object attribute order. Suggested by #3561

Checklist

• I have updated the PR title to match CDKTF's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works if applicable
• New and existing unit tests pass locally with my changes