Ender dragons do not lie down in the bed while sleeping

Ender dragons do not lie down in the bed while sleeping. Similar to armor stands, their main hitbox is still decreased. This issue relates to MC-118058.

Reproduction steps

1. /time set midnight

2. Position a bed with its foot at coordinates 0 -60 18

3. /gamerule mobGriefing false

4. /summon minecraft:ender_dragon ~ ~ ~ {SleepingX:-1,SleepingY:-60,SleepingZ:18}

   (You have the flexibility to modify the command coordinates if you've positioned the bed elsewhere.)

5. Press F3+B

Observed: The ender dragon does not lie down but retains a smaller main hitbox. (MC-148559 and MC-10919) Sleeping entities are typically rotated by 90°, but this behavior does not apply to the ender dragon in this case.
Expected: The ender dragon would lie down on the bed as well.

I abide by Minecraft's community standards and prohibit the transfer of ownership of this bug report to others. I intend to retain possession of the bug report at all times. Additionally, I should not be banned because I will continue to find more bugs and report them. Being banned would prevent me from reporting them.