'load_module()' deprecated in Python 3.12

[KumoLiu]

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/yunliu/Workspace/Code/MONAI/monai/__init__.py", line 58, in <module>
    load_submodules(sys.modules[__name__], False, exclude_pattern=excludes)
  File "/home/yunliu/Workspace/Code/MONAI/monai/utils/module.py", line 212, in load_submodules
    importer.find_spec(name).loader.load_module(name)  # type: ignore
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap_external>", line 605, in _check_name_wrapper
  File "<frozen importlib._bootstrap_external>", line 1120, in load_module
  File "<frozen importlib._bootstrap_external>", line 945, in load_module
  File "<frozen importlib._bootstrap>", line 283, in _load_module_shim
DeprecationWarning: the load_module() method is deprecated and slated for removal in Python 3.12; use exec_module() instead