Without the change `bitcoind-knots.tests` fails to evaluate:
$ nix build --no-link -f. bitcoind-knots.tests
error: attribute 'bitcoind-knots' missing
71| passthru.tests = {
72| smoke-test = nixosTests.bitcoind-knots;
| ^
73| };
From what I can see `nixos/tests/all-tests.nix` never had a
`bitcoind-knots` present.
checkInputs used to be added to nativeBuildInputs. Now we have
nativeCheckInputs to do that instead. Doing this treewide change allows
to keep hashes identical to before the introduction of
nativeCheckInputs.