fix(aztec-nr): replace deprecated BoundedVec::from_parts_unchecked with from_parts

[AztecBot]

Problem

CI on merge-train/spartan is failing in the aztec-nr step (log, sub-log c145c929c2fbaaeb):

error: `BoundedVec::from_parts` no longer requires an extra loop, `BoundedVec::from_parts_unchecked` is no longer required
   ┌─ aztec/src/note/note_getter.nr:263:17
   ┌─ aztec/src/utils/array/subbvec.nr:26:17
Aborting due to 2 previous errors

The recent noir submodule sync (#23683) deprecated BoundedVec::from_parts_unchecked. from_parts no longer zeroes elements past len in an extra loop, so the two functions are now behaviorally identical and from_parts_unchecked is marked #[deprecated]. The aztec-nr library is checked with nargo check --deny-warnings, so the deprecation warning fails the build.

Fix

Replaced every non-generated BoundedVec::from_parts_unchecked call site with BoundedVec::from_parts:

• 2 sites in aztec-nr (note_getter.nr, subbvec.nr) — these are what broke CI. Removed the now-obsolete comments explaining why the _unchecked variant was safe.
• 9 noir-protocol-circuits files (test helpers + one uniqueness-hint builder) — these only emit warnings today (those crates use plain check), migrated to clear the noise and complete the noir-sync follow-on.

The replacement is a pure behavioral no-op given the new stdlib definition (from_parts = assert(len <= MaxLen); BoundedVec { storage, len }).

Verification

Built nargo at the synced submodule commit (1.0.0-beta.21+4d0392685) and ran the same checks CI runs:

• nargo check --deny-warnings in noir-projects/aztec-nr → exit 0, no warnings (previously aborted with 2 errors).
• nargo check on private-kernel-lib, types, rollup-lib, blob → all exit 0.

The second failure in the run (bb-cpp-fuzzing) was a transient network flake — Could not resolve host: github.com while fetching msgpack-c — unrelated to this change.

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Created by claudebox · group: slackbot

[AztecBot]

Automatically closing this stale claudebox draft PR (no updates for 5+ days). Re-open if still needed.