CVE-2024-45305: gix-path uses local config across repos when it is the highest scope

gix-path executes git to find the path of a configuration file that belongs to the git installation itself, but mistakenly treats the local repository’s configuration as system-wide if no higher scoped configuration is found. In rare cases, this causes a less trusted repository to be treated as more trusted, or leaks sensitive information from one repository to another, such as sending credentials to another repository’s remote.