A0-4022: Reduced multi block contract migration weight by 4#2

Marcin-Radecki merged 2 commits intoaleph-v1.2.0aleph-zero-foundation/polkadot-sdk:aleph-v1.2.0from

decrease-contract-migration-loadaleph-zero-foundation/polkadot-sdk:decrease-contract-migration-loadCopy head branch name to clipboard