Use a scotty release version for development

In the rare case you want to use a release version (see Getting started) for development, please make sure you set the following variables before each scotty command

$ export SCOTTY_MANIFEST_OVERLAYS="-"
$ export SCOTTY_DOCKER_IMAGE="ghcr.io/avnet-embedded/scotty:scarthgap"
$ export SCOTTY_DEFAULT_MANIFEST_REVISION="scarthgap"

it is also advised to run once

$ scotty docker-update