mavsdk_tests: remove plane tests
mavsdk_tests: remove plane tests

We can put them back once it's supported.

acfloria/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,PX4/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,krbeverx/Firmware