Revert "Revert "fix(bun qc): 404 for static paths (QwikDev#6755)""

This reverts commit 4d3173c.

packages/qwik-city/src/middleware/bun/index.ts

@@ -144,6 +144,15 @@ export function createQwikCity(opts: QwikCityBunOptions) {
 
       if (isStaticPath(request.method || 'GET', url)) {
         const { filePath, content } = await openStaticFile(url);
+        // We know that it's in the static folder, but it could still be missing
+        // If we start the stream with a missing file, it will throw a 500 error during the stream
+        if (!(await content.exists())) {
+          return new Response('Not Found', {
+            status: 404,
+            headers: { 'Content-Type': 'text/plain; charset=utf-8', 'X-Not-Found': url.pathname },
+          });
+        }
+
         const ext = extname(filePath).replace(/^\./, '');
 
         return new Response(await content.stream(), {