Clean output directory before build to prevent recursive bundling (opennextjs#953)

* fix: init outDir before building next to fix recursive build

[Issue Link](https://github.com/szcharlesji/opennext-error-reproduction)

* Create soft-queens-sing.md

---------

Co-authored-by: conico974 <[email protected]>

Author: szcharlesji

.changeset/soft-queens-sing.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+Clean output directory before `next build`

packages/open-next/src/build.ts

@@ -53,11 +53,11 @@ export async function build(
   // Build Next.js app
   printHeader("Building Next.js app");
   setStandaloneBuildMode(options);
+  buildHelper.initOutputDir(options);
   buildNextjsApp(options);
 
   // Generate deployable bundle
   printHeader("Generating bundle");
-  buildHelper.initOutputDir(options);
 
   // Compile cache.ts
   compileCache(options);