Add new math functions in Python 3.11

Author: mwcraig

vpython/test/test_namespace.py

@@ -173,6 +173,11 @@ def test_names_in_base_namspace():
         for name in ['lcm', 'ulp', 'nextafter']:
             api_name_set.add(name)
 
+    # Python 3.11 adds two more new math functions.
+    if python_version.major == 3 and python_version.minor >= 11:
+        for name in ['cbrt', 'exp2']:
+            api_name_set.add(name)
+
     print(sorted(api_name_set - current_names))
 
     # We may have added new names, so start with this weaker test