feat: check noir release has nargo binaries before releasing (#22551)

## Summary
- Adds a `check_noir_release_assets` function to root `bootstrap.sh`
that queries the GitHub API to verify the noir release has nargo binary
assets
- Called from the `ci-release` case, right after semver validation and
before the build starts -- so it fails fast and only runs during
releases
- Prevents releases like `v4.2.0-aztecnr-rc.2` where the noir tag
existed but had no binaries, causing 404 errors when users ran `noirup`

## Test plan
- [x] Verified `gh release view` query returns correct asset count
against a known noir release (`v1.0.0-beta.3` → 5 assets)
- [ ] CI passes

Fixes
https://linear.app/aztec-labs/issue/F-506/check-noir-binaries-exist-on-release

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

noir/bootstrap.sh

@@ -94,11 +94,33 @@ function build {
   echo_header "noir build"
 
   if semver check $REF_NAME; then
+    # REF_NAME matches semver meaning we are doing a release
+
     git -C noir-repo fetch --tags
     if ! git -C noir-repo describe --tags --exact-match HEAD &>/dev/null; then
       echo_stderr "We're building a release but the noir-repo HEAD is not an official release."
       exit 1
     fi
+
+    # Check that the noir release has nargo binaries available for download. Without this check, we could push an aztec
+    # release that errors out with a 404/gzip error on install (the install scripts invoke noirup which would fail).
+    local noir_tag=$(git -C noir-repo describe --tags --exact-match HEAD)
+    echo "Checking noir release $noir_tag for nargo binary assets..."
+    local asset_count
+    asset_count=$(gh release view "$noir_tag" \
+      --repo noir-lang/noir \
+      --json assets \
+      --jq '[.assets[] | select(.name | test("^nargo-"))] | length') || {
+      echo_stderr "Error: Failed to query noir-lang/noir release '$noir_tag'. Does the release exist?"
+      exit 1
+    }
+    if [ "$asset_count" -eq 0 ]; then
+      echo_stderr "Error: Noir release '$noir_tag' exists but has no nargo binary assets."
+      echo_stderr "Users will get 404 errors when trying to install nargo via noirup."
+      echo_stderr "Ensure the noir release pipeline has finished uploading binaries before releasing aztec-packages."
+      exit 1
+    fi
+    echo "Found $asset_count nargo binary asset(s) in noir release $noir_tag."
   fi
 
   denoise "retry install_deps"