python3Packages.dask: fix tests

Tests cannot be ran concurrently

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

@@ -11,7 +11,6 @@
 , dill
 , pandas
 , partd
-, pytest_xdist
 }:
 
 buildPythonPackage rec {
@@ -29,7 +28,6 @@ buildPythonPackage rec {
 
   checkInputs = [
     pytestCheckHook
-    pytest_xdist # takes >10mins to run single-threaded
   ];
 
   dontUseSetuptoolsCheck = true;
@@ -54,12 +52,7 @@ buildPythonPackage rec {
       --replace "cmdclass=versioneer.get_cmdclass()," ""
   '';
 
-  # dask test suite with consistently fail when using high core counts
-  preCheck = ''
-    NIX_BUILD_CORES=$((NIX_BUILD_CORES > 8 ? 8 : NIX_BUILD_CORES))
-  '';
-
-  pytestFlagsArray = [ "-n $NIX_BUILD_CORES" ];
+  #pytestFlagsArray = [ "-n $NIX_BUILD_CORES" ];
 
   disabledTests = [
     "test_argwhere_str"