chore: remove use of pedersen where possible

[ledwards2225]

Summary of changes:

• Removed Pedersen re-exports from aztec-nr: Removed pedersen_hash and pedersen_commitment re-exports from aztec/src/hash.nr and protocol_types/src/hash.nr. (Can still use Pedersen via std::hash::pedersen_hash directly).
• Migrated production contracts to Poseidon2: Updated card_game_contract, lending_contract, and boxes/vanilla to use poseidon2_hash instead of pedersen_hash.
• Cleaned up dead C++ Pedersen code: Removed unused native Pedersen utility functions (hash_pair_native, hash_native, compute_tree_root_native, compute_tree_native) from barretenberg merkle tree infrastructure. Updated tests/benchmarks to use PedersenHashPolicy::hash_pair instead.
• Updated test contracts: Changed test_contract to import pedersen_hash_with_separator from std::hash instead of the removed aztec-nr re-export.
• Updated test snapshots: Refreshed snapshot tests in noir_test_gen.test.ts and contract_class_id.test.ts to reflect changed contract hashes.

[LeilaWang]

Thanks for removing it everywhere 🙏

[iAmMichaelConnor]

Thanks for doing this. Looks reasonable to me.
I'm not familiar with much of typescript-land, so might want sign-off from someone on that.
It's surprising how much typescript code was using pedersen -- it suggests many of those functions aren't used.

[ledwards2225]

Thanks for doing this. Looks reasonable to me. I'm not familiar with much of typescript-land, so might want sign-off from someone on that. It's surprising how much typescript code was using pedersen -- it suggests many of those functions aren't used.

Is @nventuro the right person to weigh in on the TS? if some of this code can be removed altogether then even better

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 1 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033FLAKED\033 (8;;http://ci.aztec-labs.com/d27124a74db27cf1�d27124a74db27cf18;;�): yarn-project/scripts/run_test.sh ethereum/src/l1_tx_utils/l1_tx_utils.test.ts (106s) (code: 1) group:e2e-p2p-epoch-flakes (\033ledwards2225\033: chore: remove use of pedersen where possible (#19823))