[avalanche] remove proofid from StakeCommitment ctor

Summary:
The ProofId is no longer part of the stake commitment for the proof format.

Depends on D11916

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11923