bpo-45019: Clean up the frozen __hello__ module. (gh-28374)

Here's one more small cleanup that should have been in PR gh-28319. We eliminate stdout side-effects from importing the frozen __hello__ module, and update tests accordingly. We also move the module's source file into Lib/ from Toos/freeze/flag.py.

https://bugs.python.org/issue45019

Lib/ctypes/test/test_values.py

@@ -7,7 +7,7 @@ import importlib.util
 import unittest
 import sys
 from ctypes import *
-from test.support import import_helper, captured_stdout
+from test.support import import_helper
 
 import _ctypes_test