AttributeError: module 'importlib' has no attribute 'util'

[drewoldag]

Bug report
@maxwest-uw is working with fibad and kbmod-ml, and ran into this error when trying to push changes. It's clearly lines in Fibad that are causing this:

Traceback (most recent call last):
File "/astro/users/maxwest/fibad_script.py", line 7, in
fibad_instance = fibad.Fibad(config_file="kbmod_fibad_config.toml")
File "/astro/users/maxwest/fibad/src/fibad/fibad.py", line 46, in init
self.config_manager = ConfigManager(runtime_config_filepath=config_file)
File "/astro/users/maxwest/fibad/src/fibad/config_utils.py", line 85, in init
self.external_library_config_paths = self._find_external_library_default_config_paths(
File "/astro/users/maxwest/fibad/src/fibad/config_utils.py", line 136, in _find_external_library_default_config_paths
default_configs |= ConfigManager._find_external_library_default_config_paths(value)
File "/astro/users/maxwest/fibad/src/fibad/config_utils.py", line 140, in _find_external_library_default_config_paths
if importlib.util.find_spec(external_library) is not None:
AttributeError: module 'importlib' has no attribute 'util'

[drewoldag]

I spent some time trying to reproduce this locally on the command line and wasn't able to do so. Running the following on my local machine with Python 3.11 was fine:

import importlib
importlib.util.find_spec("asdf")

In some examples of people using find_spec, I see that they typically import the following:

import importlib
import importlib.util
...

So perhaps that is necessary on some systems?

I also took a look through the python code base to see if perhaps importing just importlib would not include util, but it does seem to include it.

So I'll put together a little PR that adds the second import importlib.util statement and we can see if that fixes things.