Use readFileSync()

[styfle]

• Works: https://72401-nextjs-html-fragments-poc-git-read-file.vercel-support.app/api/fragments/foo/css
• Works: https://72401-nextjs-html-fragments-poc-git-read-file.vercel-support.app/other/fragments/foo/css
• Works: https://72401-nextjs-html-fragments-poc-git-read-file.vercel-support.app/api/hello?component=foo&format=css
• Related to Add test to ensure fs.readFile() works with Output File Tracing vercel/next.js#35338

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[styfle]

@williamli I updated to next@canary and it works now