python3Packages.nilearn: reduce test suite significantly

Full test suite attempts to pull down web resources
and can take 9+ hours with timeout periods

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

@@ -12,7 +12,8 @@ buildPythonPackage rec {
 
   checkInputs = [ pytestCheckHook ];
   disabledTests = [ "test_clean_confounds" ];  # https://github.com/nilearn/nilearn/issues/2608
-  pytestFlagsArray = [ "nilearn" ];
+  # do subset of tests which don't fetch resources
+  pytestFlagsArray = [ "nilearn/connectome/tests" ];
 
   propagatedBuildInputs = [
     joblib