I noticed that there are some empty `__init__.py` files in the repo,
with no immediately clear reason to have them. I asked [in
Discord](https://discord.com/channels/655572317891461132/655578254970716160/1211088334894534686)
and it looks like these are likely artifacts from when `lit` was used
for testing, now left over and obsolete from the migration. To keep the
repo tidy, this PR deletes the files.