create an empty folder $XDG_CONFIG_HOME/ipython

ipython partially supports xdg base directory.
Since https://github.com/ipython/ipython/pull/13224 it first checks whether `$XDG_CONFIG_HOME/ipython` is present. If it doesn't it creates its config files in `$HOME/.ipython`.
Since VSCode's flatpak has `--filesystem=host` this means that it clutters users home directory.

Do you thus think we can keep this configuration inside the ~correct directory? I know it's not strictly related to VSCode, but if an user installs the python notebook extensions his home directory is doomed to be cluttered!