Turbopack: Only benchmark file IO on `next dev` (#84474)
I added this in https://github.com/vercel/next.js/pull/66057
It's too noisy and not useful on CI. CI machines are often multi-tenant and/or running many other processes during initialization.
We could check for `process.env.CI`, but I think just having the check in `next dev` is enough.
https://vercel.slack.com/archives/C01A2M9R8RZ/p1759349240395449
