simplesat: fix outdated subsitution

Fixed upstream in https://github.com/enthought/sat-solver/commit/78ec1d8faf2a1b35a26a65c2779b80d71f4c7806

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

···
 
   pythonImportsCheck = [ "simplesat" ];
 
-  preCheck = ''
-    substituteInPlace simplesat/tests/test_pool.py \
-      --replace-fail "assertRaisesRegexp" "assertRaisesRegex"
-  '';
-
   enabledTestPaths = [ "simplesat/tests" ];
 
   meta = with lib; {