chore(nuxt): add type for headers

packages/nuxt/src/core/runtime/nitro/error.ts

@@ -45,9 +45,11 @@ export default <NitroErrorHandler> async function errorhandler (error: H3Error,
 
   // HTML response (via SSR)
   const isErrorPage = event.req.url?.startsWith('/__nuxt_error')
-  let html = !isErrorPage ? await $fetch(withQuery('/__nuxt_error', errorObject), {
-    headers: event.req.headers,
-  }).catch(() => null) : null
+  let html = !isErrorPage
+    ? await $fetch(withQuery('/__nuxt_error', errorObject), {
+      headers: event.req.headers as HeadersInit
+    }).catch(() => null)
+    : null
 
   // Fallback to static rendered error page
   if (!html) {