Refs #29926 -- Bumped minimum tblib version to 1.5.0 in test requirements.

tests/requirements/py3.txt

@@ -14,4 +14,4 @@ pywatchman; sys.platform != 'win32'
 PyYAML
 selenium
 sqlparse
-tblib
+tblib >= 1.5.0

tests/test_runner/test_parallel.py

@@ -2,7 +2,7 @@ import unittest
 
 from django.test import SimpleTestCase
 from django.test.runner import RemoteTestResult
-from django.utils.version import PY37, PY38
+from django.utils.version import PY37
 
 try:
     import tblib
@@ -63,11 +63,6 @@ class RemoteTestResultTest(SimpleTestCase):
         with self.assertRaisesMessage(TypeError, msg):
             result._confirm_picklable(not_unpicklable_error)
 
-    @unittest.skipIf(
-        PY38 and tblib is not None and tblib.__version__ <= '1.4.0',
-        'tblib <= 1.4.0 does not support Python 3.8 due to changes in the '
-        'CodeType signature (see https://bugs.python.org/issue36886).'
-    )
     @unittest.skipUnless(tblib is not None, 'requires tblib to be installed')
     def test_add_failing_subtests(self):
         """