repository: Fix ReplicateRepository test depending on host umask

One of our tests for ReplicateRepository implicitly depends on the host umask. This is becaues we have a hardcoded vote that expects a specific vote for the hooks vote, but that vote does in fact include permission bits that change depending on the current umask.

Fix this by dynamically detecting the expecte mode bits such that we can compute the expected vote instead of having to hardcode it.