Devcontainer: use "batman" user instead of root (#29704)

* devcontainer user

* cleanup permissions

* remove that

* remove that since it's not used

* clean that up after merge

* build base image first

* remove the pull

* build base image

* ensure we can pip install

* build base image as batman user

* add user uid

* add temporary comment about chown instruction

.devcontainer/Dockerfile

@@ -1,8 +1,5 @@
 FROM ghcr.io/commaai/openpilot-base:latest
 
-# remove gitconfig if exists, since its gonna be replaced by host one
-RUN rm -f /root/.gitconfig
-
 RUN apt update && apt install -y vim net-tools usbutils htop ripgrep tmux
 RUN pip install ipython jupyter jupyterlab