WARN: Remove false positive warning for iloc inplaceness
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This won't be able to set inplace, so should not warn

We are trying to cast [nan, 1.0] to integer, which raises the RuntimeWarning, but I don't think that this should leak to our users. @jbrockmendel ok to merge? We should try to get this into 1.5 too to avoid confusione some nitpicks, otherwise LGTM Thanks @phofl 