Sculk requires air above replaceable blocks in order to spread

The Bug:

Sculk requires air above replaceable blocks in order to spread.

Steps to Reproduce:

• Place down a sculk catalyst on top of some blocks that it can replace.
• Place down some torches on top of the replaceable blocks nearby.
• Spawn some entities and kill them so that sculk forms and spreads.
• Take note as to whether or not sculk requires air above replaceable blocks in order to spread.

Observed Behavior:

Sculk requires air above replaceable blocks in order to spread.

Expected Behavior:

Sculk would not require air above replaceable blocks in order to spread.