log config evaluation time (#94811)
Log how long it takes to evaluate next.configs
Sometimes it is very slow this can help users understand at least that
it is due to their config
Example dev log
```
running pnpm next --turbopack────────────────────────────────────────────────────────────────╯
▲ Next.js 16.3.0-canary.52 (Turbopack)
- Local: http://localhost:61086
- Network: http://10.103.12.203:61086
✓ Ready in 272ms
✓ Running next.config.js took 13ms
```
Example build log
```
✓ Running next.config.js took 10ms
▲ Next.js 16.3.0-canary.52 (Turbopack)
- Experiments (use with caution):
✓ mdxRs
⚠ The "middleware" file convention is deprecated. Please use "proxy" instead.
To migrate automatically, run:
npx @next/codemod@canary middleware-to-proxy .
Learn more: https://nextjs.org/docs/messages/middleware-to-proxy
Creating an optimized production build ...
```
A few things to discuss
* the bundler logging is incorrect in dev! If you use the `withRspack`
plugin it will change the bundler to rspack but the next.js version
string was already printed!
* we eval config before printing the version in build but afterwards in
dev so the evaluation timing line is a little surprising
* this demonstrates that we do evaluate the config after 'Ready in' in
dev, fine but maybe confusing for people?
