Add test teardown

Author: lukstep

test_sdk.sh

@@ -2,3 +2,5 @@ docker build . --tag lukstep/raspberry-pi-pico-sdk:latest
 docker run -d -it --name pico-sdk --mount type=bind,source=${PWD}/test_poject,target=/home/dev lukstep/raspberry-pi-pico-sdk:latest
 docker exec pico-sdk /bin/sh -c "cd /home/dev && mkdir build && cd build && cmake .. && make -j4"
 docker exec pico-sdk /bin/sh -c "picotool"
+docker container kill pico-sdk
+docker container rm pico-sdk