tests/avocado: Replace assertRegexpMatches() for Python 3.12 compatibility

assertRegexpMatches() has been removed in Python 3.12 and should be replaced by
assertRegex(). See: https://docs.python.org/3.12/whatsnew/3.12.html#id3

Inspired-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231114144832.71612-1-philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2 files changed