Signed-off-by: Austin Horstman <khaneliman12@gmail.com>
Reformat repository using new nixfmt-rfc-style.
Instead of having to manually stub packages that should not be downloaded we instead automatically stub all packages (except a small list of whitelisted ones). Tests can re-introduce the real package by using the `realPkgs` module argument.
This also reduces test flakiness.
