gh-101334: Don't force USTAR format in test_tarfile.

gpshead · gpshead · commit 2597aadec451 · 2023-02-04T16:59:18.000-08:00
That causes the test to fail when run using a high UID as that ancient format
cannot represent it. The current default (PAX) and the old default (GNU) both
support high UIDs.
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
@@ -228,7 +228,6 @@ def test_add_dir_getmember(self):
     def add_dir_and_getmember(self, name):
         with os_helper.temp_cwd():
             with tarfile.open(tmpname, 'w') as tar:
-                tar.format = tarfile.USTAR_FORMAT
                 try:
                     os.mkdir(name)
                     tar.add(name)
