fix: replace koa-helmet

Author: csikb

src/middleware/helmet.ts

@@ -9,11 +9,12 @@ import type { Middleware } from 'koa'
 export default function (options?: HelmetOptions): Middleware {
   const expressHelmet = helmet(options)
   return async (ctx, next) => {
-    return new Promise<void>((resolve, reject) => {
+    await new Promise<void>((resolve, reject) => {
       expressHelmet(ctx.req, ctx.res, (err) => {
         if (err) return reject(err)
-        resolve(next())
+        resolve()
       })
     })
+    return next()
   }
 }