Contracts verify benchmark block (#4130)

Add verify statement to ensure that benchmarks call do not revert

Also updated
[benchmarks](https://weights.tasty.limo/compare?unit=time&ignore_errors=true&threshold=10&method=asymptotic&repo=polkadot-sdk&old=master&new=pg/verify-benchmarks&path_pattern=substrate%2Fframe%2Fcontracts%2Fsrc%2Fweights.rs)

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Co-authored-by: command-bot <>