- Fix Python unit tests to use the right assert methods
- Explicitly BR python3-setuptools
`distutils` is dropped in Python 3.12, but is provided in `setuptools`;
even if we port `libkdumpfile` to use `setuptools` natively (not
possible until `Extension` is ported) we'd need to depend on
`setuptools` anyway.
Signed-off-by: Michel Alexandre Salim <salimma@fedoraproject.org>
