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.
Enabling tests is not feasible as the test suite takes > 45min (haven't
even run it to completion yet) which is not a good idea in ocamlPackages
where you often have to build from source. Additionally it would require
fetching the git repository since the test suite is not contained in the
release tarball.
Co-authored-by: locallycompact <dan.firth@homotopic.tech>