Remove pitch negation in `setpoint_rpyt`

[gemenerik]

In setpoint_rpyt, pitch is currently negated to match behavior in crazyflie-lib-python for compatibility.

crazyflie-lib-rs/src/subsystems/commander.rs

Lines 96 to 97 in 86b78f8

	// Pitch is negated for compatibility with crazyflie-lib-python
	payload.append(&mut (-pitch).to_le_bytes().to_vec());

Negations like this should not exist in our stack, values should always follow the coordinate system definition consistently. If other projects use different conventions, those adjustments should happen only at the external boundary (e.g. controller driver, external client), not here.