BrunoN builds are unsigned (no Apple Developer account), so we need to:
- Disable hardenedRuntime for BrunoN builds
- Remove identity/entitlements configuration for BrunoN
- Disable notarization (afterSign) for BrunoN builds

This fixes the macOS artifact corruption issue where unsigned apps
were being built with hardened runtime flags, which macOS treats as
corrupted/invalid.

Official Bruno builds continue to use proper code signing and
notarization as before.