With the release of macOS Sonoma (14.0), any use of matplotlib in Python code creates a warning similar to the following:
2023-11-07 07:01:09.093 Python[85638:66129140] WARNING: Secure coding is not enabled for restorable state! Enable secure coding by implementing NSApplicationDelegate.applicationSupportsSecureRestorableState: and returning YES.
I was not able to find an existing matplotlib issue related to this warning, but it relates to a known serious potential vulnerability; apparently Apple made this a warning and not an error to avoid breaking existing apps until they could be individually fixed:
Could this be fixed as part of the upcoming matplotlib release?