Setting gravity attribute to 0.0 kicks player for flying

On a dedicated server with allow-flight=false, players with a generic.gravity attribute of 0.0 are kicked the instant they are not on the ground.

To reproduce:

• Run a dedicated server with allow-flight=false
• Run /attribute @s minecraft:generic.gravity base set 0.0
• Float to a location where the block below you is air, or mine the block below you