chore(third_party): move nixkpgs-exposed to subdir to fix OWNERS r/2075

The owners plugin should in theory be able to match on subdirs (at
least according to its documentation, but it doesn’t and nobody has
any idea how to debug it.

We already know that subdirectories work just fine, so let’s go the
path of least resistance because frankly, I couldn’t care any less.

The haskell overlay also moves to the subdir, this way both can be
changed in the same go by the same people.

Change-Id: I7d98f48afa649ad2c58e38e674e1c4df09039c1c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2347
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>
Reviewed-by: lukegb <lukegb@tvl.fyi>

0 files changed, 0 insertions, 0 deletions