review dev-environment and slim it down #6665
Description
Currently dev-environment weights in at 15.2 GB (docker images).
docker pull eu.gcr.io/gitpod-core-dev/dev/dev-environment:gpl-dev-reliable-wipe.19
Depending if you happen to work on a fresh node or not, this considerably slows down workspaces starts (up to minutes!), which slows down cycles times. Also, updating the dev image takes ~20mins atm.
There should be some easy targets, like removing the QEMU VM for eBPF development (if really needed we can still leave the scripts but don't execute them during image build).
dive might be useful as well. We could also review our decision to use workspace-full-vnc as base image.