[MAINTENANCE] Fix Python 3.11 async expectations tests

[Kilo59]

This PR overwites the Maturity enum .__format__ method to presevere the backwards compatibility

The following tests fail in the Async Test pipeline due to changes in how Enums are represented as strings in formated strings in Python 3.11.
Updated the tests to remove the hard-coded enum representation.

https://docs.python.org/3/whatsnew/3.11.html#enum

FAILED tests/expectations/test_generate_diagnostic_checklist.py::test_print_diagnostic_checklist__second_iteration
FAILED tests/expectations/test_generate_diagnostic_checklist.py::test_print_diagnostic_checklist__third_iteration

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• Appropriate tests and docs have been updated

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