enable warnings as errors when testing and migrate away from deprecated import methods

[altendky]

It turns out that my import failure noted over in jaraco/keyring#683 is triggered by the fact we (not keyring) run our tests (using keyring and thus pywin32-ctypes) with warnings reported as errors. This results in pywin32-ctypes failing to be imported due to some import related warnings.

These are taken from a PR in my fork where CI is running (without approval).

https://github.com/altendky/pywin32-ctypes/actions/runs/9375227229/job/25812921472?pr=1#step:5:163

  File "D:\a\pywin32-ctypes\pywin32-ctypes\pywin32-tests\test_pywintypes.py", line 18, in <module>
    from win32ctypes import pywin32
  File "D:\a\pywin32-ctypes\pywin32-ctypes\win32ctypes\pywin32\__init__.py", line 9, in <module>
    from win32ctypes.pywin32 import win32api
  File "D:\a\pywin32-ctypes\pywin32-ctypes\win32ctypes\pywin32\win32api.py", line 9, in <module>
    from win32ctypes.core import (
  File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
ImportWarning: BackendLoader.exec_module() not found; falling back to load_module()

I'll keep this updated as I understand this better.

Looks like the fallback that is happening is to BackendLoader.load_module().

pywin32-ctypes/win32ctypes/core/__init__.py

Lines 29 to 32 in 83be1e3

	def load_module(self, fullname):
	module = importlib.import_module(self.redirect_module)
	sys.modules[fullname] = module
	return module

https://docs.python.org/3.12/library/importlib.html#importlib.abc.Loader.load_module

Deprecated since version 3.4: The recommended API for loading a module is exec_module() (and create_module()). Loaders should implement it instead of load_module(). The import machinery takes care of all the other responsibilities of load_module() when exec_module() is implemented.

There is a warning about datetime utc tz aware etc etc that haas addressed in scalative/haas@59809b1 but is not yet released.
https://github.com/altendky/pywin32-ctypes/actions/runs/9376291633/job/25815980893?pr=1#step:5:96

DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).

[itziakos]

Thanks @altendky I have added an issue to update the deprecated code.

[altendky]

Thanks for getting a change in. I missed that you had done it separately or I would have been excited sooner. :]

[itziakos]

No worries, I will upload a new wheel to pypi this week.