remove unnecessary returns

awg-cxx/lib/awg.rs

awg-cxx/lib/lib.rs

librs/actions.rs

librs/andor.rs

librs/camera.rs

librs/cli.rs

librs/colors.rs

librs/config_old.rs

librs/frame_processing/feedforward.rs

librs/frame_processing/mod.rs

librs/frame_processing/window_avg.rs

librs/lib.rs

librs/nd_utils.rs

librs/pyo3_utils.rs

librs/utils.rs

librs/viewer.rs

librs/viewer_iced.rs

timetagger-cxx/lib/lib.rs

timetagger-cxx/lib/timetagger.rs