Phantoms' rotation pitch is reversed

Phantoms have the pitch inverted compared to the rotation value. This messes up commands using local coordinates.

Steps to reproduce:

• Run the following command in a repeating command block:

  execute at @p positioned ^ ^ ^5 as @e[type=phantom] run teleport @s ~ ~ ~ ~ ~

• observe the phantom's facing direction

Expected result:

The phantom has the same facing direction as you.

Actual result:
The phantom faced up when you face down, and vice versa.