rust-index: drop offset_override The inline `offsets` value diverge from the one on disk for added value, so the offset_override tricks is not going to work well once we start having the full revlog logic in Rust. We remove it beforehand and align the Rust logic to the Python one (adjusting the segment offset at read time for inline revlog).

rust-index: stop calling `with_offset` in the tests We are not adding any data, so why are we setting any offset?