Issue #25607: Restore old distutils logging threshold after running tests that

parse command line arguments.

tests/test_core.py

@@ -9,6 +9,7 @@ import test.support
 from test.support import captured_stdout, run_unittest
 import unittest
 from distutils.tests import support
+from distutils import log
 
 # setup script that uses __file__
 setup_using___file__ = """\
@@ -36,6 +37,7 @@ class CoreTestCase(support.EnvironGuard, unittest.TestCase):
         self.old_stdout = sys.stdout
         self.cleanup_testfn()
         self.old_argv = sys.argv, sys.argv[:]
+        self.addCleanup(log.set_threshold, log._global_log.threshold)
 
     def tearDown(self):
         sys.stdout = self.old_stdout

tests/test_dist.py

@@ -13,6 +13,7 @@ from distutils.cmd import Command
 
 from test.support import TESTFN, captured_stdout, run_unittest
 from distutils.tests import support
+from distutils import log
 
 
 class test_dist(Command):
@@ -405,6 +406,7 @@ class MetadataTestCase(support.TempdirManager, support.EnvironGuard,
 
     def test_show_help(self):
         # smoke test, just makes sure some help is displayed
+        self.addCleanup(log.set_threshold, log._global_log.threshold)
         dist = Distribution()
         sys.argv = []
         dist.help = 1