Update Dockerfile to omit mkdocs so that pre-builds will complete successfully

[nickfloyd]

Currently prebuilds are failing and we might need to move from python3-pip to python3-full which will add build time and a few other variables into our pipeline. Looking to put in a simple workaround for now (so that codespaces spin up does not cause a huge time delay as well as to fix create code spaces functionally from GitHub.com