remove cond

Author: huozhi

packages/next/src/build/index.ts

@@ -3009,12 +3009,6 @@ export default async function build(
             ]
 
             for (const prerenderedRoute of prerenderedRoutes) {
-              // TODO: check if still needed?
-              // Exclude the /_not-found route.
-              if (prerenderedRoute.pathname === UNDERSCORE_NOT_FOUND_ROUTE) {
-                continue
-              }
-
               if (
                 isRoutePPREnabled &&
                 prerenderedRoute.fallbackRouteParams &&
@@ -3637,23 +3631,6 @@ export default async function build(
           await writeManifest(pagesManifestPath, pagesManifest)
         })
 
-        const hasStaticAppRouterNotFound = existsSync(
-          path.join(distDir, 'server', 'app', '_not-found.html')
-        )
-        // If the _not-found.html exists, add /_not-found to the prerender manifest
-        if (hasStaticAppRouterNotFound) {
-          prerenderManifest.routes['/_not-found'] = {
-            initialRevalidateSeconds: false,
-            initialExpireSeconds: undefined,
-            experimentalPPR: undefined,
-            renderingMode: undefined,
-            srcRoute: null,
-            dataRoute: null,
-            prefetchDataRoute: null,
-            allowHeader: ALLOWED_HEADERS,
-          }
-        }
-
         // As we may have modified the dynamicRoutes, we need to sort the
         // dynamic routes by page.
         routesManifest.dynamicRoutes = sortSortableRouteObjects(