Fix x64 macOS build bundling wrong architecture binaries

Set YAAK_TARGET_ARCH before npm run bootstrap so vendor scripts
download the correct x64 binaries instead of arm64 ones.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gschier

.github/workflows/release.yml

@@ -89,6 +89,8 @@ jobs:
 
       - run: npm ci
       - run: npm run bootstrap
+        env:
+          YAAK_TARGET_ARCH: ${{ matrix.yaak_arch }}
       - run: npm run lint
       - name: Run JS Tests
         run: npm test