Add `structuredClone` to benchmarks

[silverwind]

https://developer.mozilla.org/en-US/docs/Web/API/structuredClone

In my limited testing, it's around 2-3 times slower than this module with proto: false, circles: true options.

[Matteo Collina]

would you like to send a PR? Adding that it would be awesome.

[silverwind]

Could have a look I guess. It will require Node.js 17 or higher.

[Matteo Collina]

For benchmarks it's ok

[Raz Luvaton]

I see @mcollina added it in 60507bf but did not update the readme with the results

[Matteo Collina]

Done