Correct the price to verify native signatures

[Voxelot]

closes: #757

Use secp256k1 instead of secp256r1 gas price when validating native signatures on UTXOs.

Checklist

• Breaking changes are clearly marked as such in the PR description and changelog
• New behavior is reflected in tests
• If performance characteristic of an instruction change, update gas costs as well or make a follow-up PR for that
• The specification matches the implemented behavior (link update PR if changes are needed)

Before requesting review

• I have reviewed the code myself
• I have created follow-up issues caused by this PR and linked them here

After merging, notify other teams

[Add or remove entries as needed]

• Rust SDK

[Voxelot]

holding off on this due to potential backwards compatibility issues