Support vitest v4

[adriencaccia]

Vitest v4 is now availalable, and it seems that it does play well well with @codspeed/vitest-plugin yet.

This issue will track its support.

Fix #66, #54

[bernardobelchior]

We've just upgraded to v4 and benchmarks aren't showing up, even though they run and show that data was uploaded. Here's the job run. Here's the PR.