Add a new home-manager-compatible configuration file which loads the
common config attrset used by the readTree machinery into a structure
which the home-manager command line tool understands.
Garbage-collect the old home-manager configuration file used on whitby,
and update the HOME_MANAGER_CONFIG path to point at the new shim config.
Instead of having a per-environment HM configuration (not that I have
more than one environment), there's now a single configuration which
evaluates to an attrset of configurations, which can be loaded and built
using "home-manager build -A $attr".
Change-Id: Id8b35dc89aabffedf1a4dadfa0d3d4b914e4e2e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2129
Tested-by: BuildkiteCI
Reviewed-by: multi <depot@in-addr.xyz>
7ff2142f19
