use sudo for pruning docker images

[lachsdachs]

The last part of the Docker update step was giving me the following error:

permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Head "http://%2Fvar%2Frun%2Fdocker.sock/_ping": dial unix /var/run/docker.sock: connect: permission denied
ERROR Removing dangling images failed: Command failed: '/usr/local/bin/docker image prune -f'

Manually executing /usr/local/bin/docker image prune -f with sudo worked fine, so i'm assuming that this was really just a permissions thing. I have not tested this fix and i'm not sure if i implemented it correctly, so please check the code. It seems weird that this issue has not come up before, could it be OS or distribution specific? I'm running Bedrock Linux/Kubuntu.

[lachsdachs]

oh no