test: make middleware fixture produce chunked middleware

Author: pieh

tests/fixtures/middleware/next.config.js

@@ -4,6 +4,11 @@ const nextConfig = {
   eslint: {
     ignoreDuringBuilds: true,
   },
+  webpack: (config) => {
+    config.optimization.splitChunks.maxSize = 100_000
+
+    return config
+  }
 }
 
 module.exports = nextConfig