Setting coalesce=0 when calling get_ranges doesn't disable coalescing

[talawahtech]

According to the get_ranges docs for the coalesce param you can "Set to 0 to disable coalescing", but in my testing this doesn't actually work if I want to download adjacent ranges in parallel.

Taking a quick look at the merge_ranges code in arrow-rs-object-store it seems that the comparison is <= so I guess the documentation is wrong.

Would be nice to actually have this feature though.

[kylebarron]

Hmm there should probably be an early exit around here https://github.com/apache/arrow-rs-object-store/blob/706b7d8b536fd02a8a323bb8dbeae344fc8d65eb/src/util.rs#L140-L142 that just says if coalesce == 0 return existing ranges

Would you be able to make an upstream issue and/or submit a PR?