movement_speed base attribute is reset upon world load.

Steps to reproduce:

1. Load a world with commands enabled

2. Run the following command:

   /attribute @s minecraft:movement_speed base set 2.0

3. Observe the speed increase

4. Reload the world

5. The speed increase is reset

What happens when the bug occurs:

• The speed is set back to the default

• You can see the FOV reset

Expected result:

• The speed attribute stays at 2.0

Additional notes:

• This only applies to the movement_speed attribute

• This does not happen when the movement speed is changed via a modifier

  /attribute @s minecraft:movement_speed modifier add test:test 2.0 add_value