Debian has enabled `EXTERNALLY-MANAGED` from PEP 668 which breaks `pip
install --user`. I think this is a terrible decision, understandable to
want to avoid modifications in `/usr/lib/python*/site-packages` but to
have that stop be installing packages in my home directory is a big
mistake in terms of usability. In any case this patch moves the
configuration of `pip.conf` to occur before any other roles are
processed, seting the override flag, even though I'm never actually
touching the real site packages.
