test: convert middleware-conditions fixture to page router, as app router with i18n enabled fails to build on next@canary now

Author: pieh

tests/fixtures/middleware-conditions/app/layout.js

@@ -0,0 +1,16 @@
+export default function Page({ message }) {
+  return (
+    <main>
+      <h1>Message from middleware: {message}</h1>
+    </main>
+  )
+}
+
+/** @type {import('next').GetServerSideProps} */
+export const getServerSideProps = async (ctx) => {
+  return {
+    props: {
+      message: ctx.req.headers['x-hello-from-middleware-req'] || null,
+    },
+  }
+}