feat(hashing): use domain-separated leaf hashing in SMT

[gswirski]

Update SMT hashing to follow: #2996 (comment) and 0xMiden/crypto#962 implementation.

[github-actions]

Automated check (CONTRIBUTING.md)

Findings:

• Ensure issue Update the VM core library to use domain-separated leaf hashing #2996 is assigned to the PR author.
• Add a short Rationale explaining why the change is needed.

Recommendations:

• Consider adding a Test plan or clear review steps.

Next steps:

• Ensure issue Update the VM core library to use domain-separated leaf hashing #2996 is assigned to you.
• See CONTRIBUTING.md for expectations.
• If this is a false positive, comment: /quality-review.