New cost model for signatures

[0x0ece]

The cost model for signatures changed: https://github.com/anza-xyz/agave/blob/v2.0.1/cost-model/src/cost_model.rs#L53

vs

https://github.com/firedancer-io/firedancer/blob/f383c75ba3a32b039faf751ca00b954d4409aa53/src/flamenco/runtime/fd_runtime.c#L2652-L2667

cc @jumpsiegel