[NEXT-696] New middleware slows down routing in production

### Verify canary release - [X] I verified that the issue exists in the latest Next.js canary release ### Provide environment information Operating System: Platform: win32 Arch: x64 Version: Windows 10 Pro Binaries: Node: 16.14.2 npm: N/A Yarn: N/A pnpm: N/A Relevant packages: next: 12.2.0 eslint-config-next: 12.2.0 react: 18.2.0 react-dom: 18.2.0 ### What browser are you using? (if relevant) Chrome 103.0.5060.66 ### How are you deploying your application? (if relevant) next start ### Describe the Bug New middleware slows down on routing in production (dev is okay), example code that slows down: ```js import { NextResponse } from 'next/server'; const Middleware = (req) => { /** To lower case redirect. */ if (req.nextUrl.pathname === req.nextUrl.pathname.toLowerCase()) return NextResponse.next(); return NextResponse.redirect(new URL(req.nextUrl.origin + req.nextUrl.pathname.toLowerCase())); }; export default Middleware; ``` ### Expected Behavior Work as expected with no slow down, with previous `_middleware.js` there was no problem ### To Reproduce Create `middleware.js` file under root folder and use code from example _{[NEXT-696](https://linear.app/vercel/issue/NEXT-696/new-middleware-slows-down-routing-in-production)}