[dask] [ci] add support for scikit-learn 0.24+ in tests (fixes #4031) (#4032)

* [dask] [ci] add support for scikit-learn 0.24+ in tests (fixes #4031)

* Update tests/python_package_test/test_dask.py
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* try upgrading mixtexsetup

* they changed the executable name UGH

* more changes for executable name

* another path change

* changing package mirrors

* undo experiments
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

tests/python_package_test/test_dask.py

@@ -28,12 +28,16 @@ import sklearn.utils.estimator_checks as sklearn_checks
 from dask.array.utils import assert_eq
 from dask.distributed import Client, LocalCluster, default_client, wait
 from distributed.utils_test import client, cluster_fixture, gen_cluster, loop
+from pkg_resources import parse_version
 from scipy.sparse import csr_matrix
 from scipy.stats import spearmanr
+from sklearn import __version__ as sk_version
 from sklearn.datasets import make_blobs, make_regression
 
 from .utils import make_ranking
 
+sk_version = parse_version(sk_version)
+
 # time, in seconds, to wait for the Dask client to close. Used to avoid teardown errors
 # see https://distributed.dask.org/en/latest/api.html#distributed.Client.close
 CLIENT_CLOSE_TIMEOUT = 120
@@ -1253,5 +1257,9 @@ def test_sklearn_integration(estimator, check, client):
 # this test is separate because it takes a not-yet-constructed estimator
 @pytest.mark.parametrize("estimator", list(_tested_estimators()))
 def test_parameters_default_constructible(estimator):
-    name, Estimator = estimator.__class__.__name__, estimator.__class__
+    name = estimator.__class__.__name__
+    if sk_version >= parse_version("0.24"):
+        Estimator = estimator
+    else:
+        Estimator = estimator.__class__
     sklearn_checks.check_parameters_default_constructible(name, Estimator)