The version of mfa_factor_token in the third party plugin for Moodle 4.1 (https://github.com/catalyst/moodle-tool_mfa/blob/MOODLE_400_STABLE/factor/token/version.php#L29) is higher than the version integrated in Moodle 4.3 core. This causes an error during the upgrade if mfa was already installed as third party plugin:

A workaround is described at https://github.com/catalyst/moodle-tool_mfa/issues/457. To make to upgrade easier for everyone, the version in the Moodle core should be bumped (not everyone wants to fiddle around in the database).