Rain only affects entities if the center of their hitbox is in contact with the rain

The Bug:

Rain only affects entities if the center of their hitbox is in contact with the rain.

Steps to Reproduce:

1. Set the weather to "rain" and give yourself a trident enchanted with riptide by using the command provided below.

   /give @s minecraft:trident[minecraft:enchantments={levels:{"minecraft:riptide":3}}]

2. Place a block floating in the air and stand under it so you're shielded from the rain.
3. Allow part of your hitbox to be in contact with the rain and attempt to use your trident enchanted with riptide.

Observed Behavior:

Rain only affects entities if the center of their hitbox is in contact with the rain.

Expected Behavior:

Rain would affect entities if any part of their hitbox is in contact with the rain.