fix(nextjs): Update clerkMiddleware type (#5470)

Author: jacekradko

.changeset/cool-houses-bake.md

@@ -0,0 +1,5 @@
+---
+'@clerk/nextjs': patch
+---
+
+Fixing a Typing error in clerkMiddleware

packages/nextjs/src/server/clerkMiddleware.ts

@@ -94,12 +94,11 @@ interface ClerkMiddleware {
 /**
  * The `clerkMiddleware()` helper integrates Clerk authentication into your Next.js application through Middleware. `clerkMiddleware()` is compatible with both the App and Pages routers.
  */
-// @ts-expect-error TS is not happy here. Will dig into it
-export const clerkMiddleware: ClerkMiddleware = (...args: unknown[]) => {
+export const clerkMiddleware = ((...args: unknown[]): NextMiddleware | NextMiddlewareReturn => {
   const [request, event] = parseRequestAndEvent(args);
   const [handler, params] = parseHandlerAndOptions(args);
 
-  return clerkMiddlewareRequestDataStorage.run(clerkMiddlewareRequestDataStore, () => {
+  const middleware = clerkMiddlewareRequestDataStorage.run(clerkMiddlewareRequestDataStore, () => {
     const baseNextMiddleware: NextMiddleware = withLogger('clerkMiddleware', logger => async (request, event) => {
       // Handles the case where `options` is a callback function to dynamically access `NextRequest`
       const resolvedParams = typeof params === 'function' ? await params(request) : params;
@@ -263,7 +262,9 @@ export const clerkMiddleware: ClerkMiddleware = (...args: unknown[]) => {
     // eg, export default clerkMiddleware(auth => { ... });
     return nextMiddleware;
   });
-};
+
+  return middleware;
+}) as ClerkMiddleware;
 
 const parseRequestAndEvent = (args: unknown[]) => {
   return [args[0] instanceof Request ? args[0] : undefined, args[0] instanceof Request ? args[1] : undefined] as [