pythonPackages.blis: add missing dependency numpy

blis' numpy dependency seems to have been falsely satisfied by its
inclusion in checkInputs, whereas this seems to actually be an install
dependency. this can be demonstrated by attempting to build this package
with doCheck = false and watching it fail.

also removed cython from checkInputs as it's already in nativeBuildInputs

pkgs/development/python-modules/blis/default.nix

@@ -20,11 +20,13 @@ buildPythonPackage rec {
     cython
   ];
 
+  propagatedBuildInputs = [
+    numpy
+  ];
+
 
   checkInputs = [
-    cython
     hypothesis
-    numpy
     pytest
   ];