hotfix: reduce image size by ~50%

[beniaminopozzan]

px4_sitl bin folder was copied without preserving simlinks the resulting docker layer was 4GB instead of 50MB (approximate)

before:

ubuntu@55f8a4c7d61d:~/px4_sitl$ du ./bin/*
53872   ./bin/px4
53872   ./bin/px4-actuator_test
53872   ./bin/px4-airship_att_control
53872   ./bin/px4-airspeed_selector
8       ./bin/px4-alias.sh
53872   ./bin/px4-attitude_estimator_q
53872   ./bin/px4-battery_simulator
53872   ./bin/px4-bsondump
53872   ./bin/px4-camera_feedback
53872   ./bin/px4-camera_trigger
53872   ./bin/px4-cdev_test
53872   ./bin/px4-commander
53872   ./bin/px4-control_allocator
53872   ./bin/px4-controllib_test
53872   ./bin/px4-dataman
53872   ./bin/px4-dyn
53872   ./bin/px4-ekf2
53872   ./bin/px4-failure
53872   ./bin/px4-fake_gps
53872   ./bin/px4-fake_imu
53872   ./bin/px4-fake_magnetometer
53872   ./bin/px4-flight_mode_manager
53872   ./bin/px4-fw_att_control
53872   ./bin/px4-fw_autotune_attitude_control
53872   ./bin/px4-fw_pos_control
53872   ./bin/px4-fw_rate_control
53872   ./bin/px4-gimbal
53872   ./bin/px4-gps
53872   ./bin/px4-gyro_calibration
53872   ./bin/px4-gyro_fft
53872   ./bin/px4-gz_bridge
53872   ./bin/px4-hello
53872   ./bin/px4-hrt_test
53872   ./bin/px4-land_detector
53872   ./bin/px4-landing_target_estimator
53872   ./bin/px4-led_control
53872   ./bin/px4-listener
53872   ./bin/px4-load_mon
53872   ./bin/px4-local_position_estimator
53872   ./bin/px4-logger
53872   ./bin/px4-mag_bias_estimator
53872   ./bin/px4-manual_control
53872   ./bin/px4-mavlink
53872   ./bin/px4-mavlink_tests
53872   ./bin/px4-mc_att_control
53872   ./bin/px4-mc_autotune_attitude_control
53872   ./bin/px4-mc_hover_thrust_estimator
53872   ./bin/px4-mc_pos_control
53872   ./bin/px4-mc_rate_control
53872   ./bin/px4-msp_osd
53872   ./bin/px4-navigator
53872   ./bin/px4-param
53872   ./bin/px4-payload_deliverer
53872   ./bin/px4-perf
53872   ./bin/px4-pwm_out_sim
53872   ./bin/px4-px4_mavlink_debug
53872   ./bin/px4-px4_simple_app
53872   ./bin/px4-rc_tests
53872   ./bin/px4-rc_update
53872   ./bin/px4-replay
53872   ./bin/px4-rover_ackermann
53872   ./bin/px4-rover_differential
53872   ./bin/px4-rover_mecanum
53872   ./bin/px4-rover_pos_control
53872   ./bin/px4-sd_bench
53872   ./bin/px4-send_event
53872   ./bin/px4-sensor_agp_sim
53872   ./bin/px4-sensor_airspeed_sim
53872   ./bin/px4-sensor_baro_sim
53872   ./bin/px4-sensor_gps_sim
53872   ./bin/px4-sensor_mag_sim
53872   ./bin/px4-sensors
53872   ./bin/px4-shutdown
53872   ./bin/px4-simulator_mavlink
53872   ./bin/px4-simulator_sih
53872   ./bin/px4-system_power_simulator
53868   ./bin/px4-system_time
53868   ./bin/px4-temperature_compensation
53872   ./bin/px4-tests
53872   ./bin/px4-tone_alarm
53872   ./bin/px4-tune_control
53872   ./bin/px4-uorb
53872   ./bin/px4-uorb_tests
53872   ./bin/px4-uuv_att_control
53872   ./bin/px4-uuv_pos_control
53872   ./bin/px4-uxrce_dds_client
53872   ./bin/px4-ver
53872   ./bin/px4-vtol_att_control
53872   ./bin/px4-work_item_example
53872   ./bin/px4-work_queue
53872   ./bin/px4-wqueue_test

after

ubuntu@555bc4f949d5:~/px4_sitl$ du bin/*
53872   bin/px4
0       bin/px4-actuator_test
0       bin/px4-airship_att_control
0       bin/px4-airspeed_selector
8       bin/px4-alias.sh
0       bin/px4-attitude_estimator_q
0       bin/px4-battery_simulator
0       bin/px4-bsondump
0       bin/px4-camera_feedback
0       bin/px4-camera_trigger
0       bin/px4-cdev_test
0       bin/px4-commander
0       bin/px4-control_allocator
0       bin/px4-controllib_test
0       bin/px4-dataman
0       bin/px4-dyn
0       bin/px4-ekf2
0       bin/px4-failure
0       bin/px4-fake_gps
0       bin/px4-fake_imu
0       bin/px4-fake_magnetometer
0       bin/px4-flight_mode_manager
0       bin/px4-fw_att_control
0       bin/px4-fw_autotune_attitude_control
0       bin/px4-fw_pos_control
0       bin/px4-fw_rate_control
0       bin/px4-gimbal
0       bin/px4-gps
0       bin/px4-gyro_calibration
0       bin/px4-gyro_fft
0       bin/px4-gz_bridge
0       bin/px4-hello
0       bin/px4-hrt_test
0       bin/px4-land_detector
0       bin/px4-landing_target_estimator
0       bin/px4-led_control
0       bin/px4-listener
0       bin/px4-load_mon
0       bin/px4-local_position_estimator
0       bin/px4-logger
0       bin/px4-mag_bias_estimator
0       bin/px4-manual_control
0       bin/px4-mavlink
0       bin/px4-mavlink_tests
0       bin/px4-mc_att_control
0       bin/px4-mc_autotune_attitude_control
0       bin/px4-mc_hover_thrust_estimator
0       bin/px4-mc_pos_control
0       bin/px4-mc_rate_control
0       bin/px4-msp_osd
0       bin/px4-navigator
0       bin/px4-param
0       bin/px4-payload_deliverer
0       bin/px4-perf
0       bin/px4-pwm_out_sim
0       bin/px4-px4_mavlink_debug
0       bin/px4-px4_simple_app
0       bin/px4-rc_tests
0       bin/px4-rc_update
0       bin/px4-replay
0       bin/px4-rover_ackermann
0       bin/px4-rover_differential
0       bin/px4-rover_mecanum
0       bin/px4-rover_pos_control
0       bin/px4-sd_bench
0       bin/px4-send_event
0       bin/px4-sensor_agp_sim
0       bin/px4-sensor_airspeed_sim
0       bin/px4-sensor_baro_sim
0       bin/px4-sensor_gps_sim
0       bin/px4-sensor_mag_sim
0       bin/px4-sensors
0       bin/px4-shutdown
0       bin/px4-simulator_mavlink
0       bin/px4-simulator_sih
0       bin/px4-system_power_simulator
0       bin/px4-system_time
0       bin/px4-temperature_compensation
0       bin/px4-tests
0       bin/px4-tone_alarm
0       bin/px4-tune_control
0       bin/px4-uorb
0       bin/px4-uorb_tests
0       bin/px4-uuv_att_control
0       bin/px4-uuv_pos_control
0       bin/px4-uxrce_dds_client
0       bin/px4-ver
0       bin/px4-vtol_att_control
0       bin/px4-work_item_example
0       bin/px4-work_queue
0       bin/px4-wqueue_test

docker images sizes

~/git/roscon-25-workshop$ docker images
REPOSITORY                                                                                    TAG                           IMAGE ID       CREATED          SIZE
dronecode/roscon-25-workshop                                                                  latest                        0e8cfc8a4e69   8 minutes ago    4.01GB
dronecode/roscon-25-workshop                                                                  <none>                        b77eabf8931d   8 hours ago      8.98GB