python311.pkgs.nipy: fix build

We have to regenerate the Cython C files for Python 3.11
compatibility.  This is a nice thing to be doing anyway, from a
bootstrappability point of view.

Link: https://github.com/nipy/nipy/issues/496#issuecomment-1382736563

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

@@ -2,6 +2,7 @@
 , buildPythonPackage
 , fetchPypi
 , pythonOlder
+, cython
 , nose
 , matplotlib
 , nibabel
@@ -21,9 +22,14 @@ buildPythonPackage rec {
     sha256 = "a8a2c97ce854fece4aced5a6394b9fdca5846150ad6d2a36b86590924af3c848";
   };
 
+  nativeBuildInputs = [ cython ];
   buildInputs = lib.optionals doCheck [ nose ];
   propagatedBuildInputs = [ matplotlib nibabel numpy scipy sympy ];
 
+  preBuild = ''
+    make recythonize
+  '';
+
   checkPhase = ''    # wants to be run in a different directory
     mkdir nosetests
     cd nosetests