make new Response() returns text/plain (solidjs#1912)

Author: huseeiin

.changeset/tough-towns-pick.md

@@ -0,0 +1,5 @@
+---
+"@solidjs/start": patch
+---
+
+now using respondWith or node.res.end will behave correctly

packages/start/src/server/handler.ts

@@ -59,6 +59,7 @@ export function createBaseHandler(
               `API handler for ${event.request.method} "${event.request.url}" did not return a response.`
             );
           }
+          return;
         }
 
         // render