The bug

When a blaze shoots a fireball, sculk sensors do not detect this, despite this being a projectile fired.

According to the 20w49a patch notes, projectiles being fired is considered a vibration.

How to reproduce

1. Construct the blaze container, as shown here:
   
2. Spawn a blaze inside of the container, and stand far enough back so that the sculk sensor does not detect your footsteps
3. Enter survival mode (/gamemode survival)
4. Wait for the blaze to begin shooting fireballs