fix: 🐛 use MaxKeys from pallet-im-online's Config trait instead of hardcoded one in benchmarks#9325

bkchr merged 2 commits intoparitytech:masterparitytech/polkadot-sdk:masterfrom

TDemeco:fix/pallet-im-online-benchmarkTDemeco/polkadot-sdk:fix/pallet-im-online-benchmarkCopy head branch name to clipboard