Withers below half health can be hit by wither skulls

Withers below half health can be hit by wither skulls (including their own, in the unlikely event they should appear in the path of one), and will take damage. As wither armor was not detailed in the 12w34b changelog, it is unknown whether this is intended, but the behavior is inconsistent with breezes since 24w03a.

To reproduce

1. Launch the game with output enabled

2. /summon wither ~ ~ ~ {Silent:1b,NoAI:1b,Health:10f}

3. /data get entity @s UUID

4. Copy your UUID from the game output

5. Position yourself a couple of blocks west of the wither, and face it

6. /summon minecraft:wither_skull ^ ^ ^1 {Motion:[1d,0d,0d],Owner:YOUR_UUID_HERE}
   The wither is hit by the wither skull and takes damage