Revert "xfail async scenarios test on py3.10"

This reverts commit abbf669.

Author: graingert

tests/feature/test_async_scenarios.py

@@ -1,15 +1,9 @@
 """Test scenarios shortcut."""
-import sys
 import textwrap
 
-import pytest
-
 from tests.utils import assert_outcomes
 
 
-@pytest.mark.xfail(
-    sys.version_info >= (3, 10), reason="trio does not support py3.10 https://github.com/python-trio/trio/pull/1921"
-)
 def test_scenarios(testdir, pytest_params):
     """Test scenarios shortcut (used together with @scenario for individual test override)."""
     testdir.makeini(