Yaw and pitch changes apply incorrectly to player entities.

[YotaXP]

When changing a player entity's facing direction with modify(_, 'location', ...), modify(_, 'yaw', ...), or modify(_, 'pitch', ...), the entity's initial facing direction is influencing the result. Furthermore, modifying 'yaw' also affects pitch, and vice versa.

For example, running following command while I have a yaw and pitch of 15, 10 adjusts my yaw AND pitch to 17, 20.
/script run modify(player(), 'yaw', 2)
I would expect my yaw and pitch to be 2, 10 afterwards.

This only occurs with player entities from what I've seen. Setting the pitch and yaw of mobs works correctly.

Workarounds:

set_direction(player, yaw, pitch) ->
    modify(player, 'location', ...player~'pos', yaw - player~'yaw', pitch - player~'pitch')

set_yaw(player, yaw) ->
    modify(player, 'location', ...player~'pos', yaw - player~'yaw', 0)

set_pitch(player, pitch) ->
    modify(player, 'location', ...player~'pos', 0, pitch - player~'pitch')

This appears to be a regression as it did not always behave this way.

I have tested and found this behavior in the following versions:

Minecraft: 1.21.3 - Fabric: 0.16.9 - Carpet: 1.4.158
Minecraft: 1.21.4 - Fabric: 0.16.10 - Carpet: 1.4.161