Players can still get kill rewards if they are spectators

[jellz]

Describe the bug
Players can get kill rewards when they're not in the game

Client version
1.8.9 Lunar Client

To Reproduce

1. Hit someone into the void on a map that has kill rewards
2. Join Spectators (/join sp)
3. When the player falls in the void and dies, you will get the kill rewards

Expected behaviour
The spectator should not get the kill rewards.

Screenshots

I received a golden apple as a spectator

Server Software (Spigot/PaperSpigot):
Paper 1.15.2