Mobs suffocate inside most copper grate block variants

The bug

The 23w43a changelogs say "Mobs cannot suffocate inside" copper grates, but they actually do (they suffocate players too). The only copper grate that doesn't suffocate entities is the default (non-waxed, non-oxidized) copper grate.

Steps to reproduce

1. Place copper grate 1 block above the ground
2. Spawn a creeper below the grate
3. Notice the creeper suffocates