Fix the lingering meteo particle bug

MR Description

• This MR fixes a meteo problem PSDK seem to have since long ago. When switching from a map with a meteo (generally rain/snow/sandstorm) to a map without any meteo, some particles weren't correctly hidden, leading to a ghost particle still visible on the next maps.

Note to acknowledge before testing

• When you want to check whether a particule is still visible or not, you can use the following command in the console:

$scene.spriteset.instance_variable_get(:@weather).instance_variable_get(:@sprites).any?(&:visible)

If the console displays "false", it means no particle exist on the screen, thus validating the test

Tests to realize

• Switch from a map which has a snowy meteo to a meteo-free map: you shouldn't have any snowflake on the screen anywhere on the current map, and the command should send back "false".
• Switch from a map which has a rainy meteo to a meteo-free map: you shouldn't have any raindrop on the screen anywhere on the current map, and the command should send back "false".
• Switch from a map which has a sandstorm meteo to a meteo-free map: you shouldn't have any sand on the screen anywhere on the current map, and the command should send back "false".