Replace deprecated logging function

[stefanvi]

Description

Python's logging.warn is deprecated and should be replaced by the functionally equivalent logging.warning. As mentioned in the documentation of the logging module

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Functionally equivalent.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[mkultraWasHere]

ty @stefanvi