Closes #11279: test_posix and lack of "id -G" support - less noise required? (Solaris)

Lib/test/test_posix.py

@@ -757,7 +757,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(os, 'getegid'), "test needs os.getegid()")
     def test_getgroups(self):
-        with os.popen('id -G') as idg:
+        with os.popen('id -G 2>/dev/null') as idg:
             groups = idg.read().strip()
             ret = idg.close()