AI: new_bonus can overflow int64
Ref: https://tezos-dev.slack.com/archives/C05RS0MEJ9H/p1694531207583519
https://gitlab.com/tezos/tezos/-/blob/master/src/proto_018_Proxford/lib_protocol/adaptive_issuance_storage.ml?ref_type=heads#L162 is it intended new_bonus can exceed Int64.max_int?
Safest solution: stay in Q until we're in the correct bounds
Edited by Julien