Removed accel_to_decel from the SET_VELOCITY_LIMIT in TEST_SPEED.cfg

[theogayar]

It seems that the macro was never updated following Klipper's deprecation of "ACCEL_TO_DECEL"

This PR simply aims to remove the error message that gets thrown by klipper every time the macro is called :

Error on 'SET_VELOCITY_LIMIT VELOCITY=500.0 ACCEL=4000.0 ACCEL_TO_DECEL=': unable to parse

See : Klipper's config changelog on 20240313

20240313: The max_accel_to_decel parameter in the [printer] config section has been deprecated. The ACCEL_TO_DECEL parameter of the SET_VELOCITY_LIMIT command has been deprecated. The printer.toolhead.max_accel_to_decel status has been removed. Use the minimum_cruise_ratio parameter instead. The deprecated features will be removed in the near future, and using them in the interim may result in subtly different behavior.