[Regression] Can no longer /kill targets (including self) in Creative Mode

If you try to /kill a target and that target is in Creative Mode, they cannot be killed. This makes quickly respawning yourself (/kill @s) especially tedious or other Creative users who are maybe lost and want to quickly get back to spawn.

If you try to kill a target that is in Creative Mode, you get a message in red that says No targets matched selector.

This issue only popped up after updating to 1.10.0.7.