Fix: Process MIR at epoch boundary

[golddydev]

Story

We need to process MIR at epoch boundary.

Reference

This is EPOCH rule of haskell code.
https://github.com/IntersectMBO/cardano-ledger/blob/24ef1741c5e0109e4d73685a24d8e753e225656d/eras/shelley/impl/src/Cardano/Ledger/Shelley/Rules/NewEpoch.hs#L160

Acceptance Criteria

• Process MIR at the epoch boundary