Add //nix/writeTree, a function to make a derivation to build a
directory structure from a Nix attribute set.
Co-authored-by: sterni <sternenseemann@systemli.org>
Change-Id: I9c0fc91611a55a20ad33de6f2b27abde4b6abd21
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10963
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: aspen <root@gws.fyi>
