Remove duplicate catch block in checkout route

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/app/api/checkout/route.ts

@@ -153,8 +153,4 @@ export async function POST(req: Request) {
     console.error('Returning error to client:', message);
     return NextResponse.json({ error: message }, { status: 500 });
   }
-  } catch (err) {
-    const message = err instanceof Error ? err.message : 'Something went wrong.';
-    return NextResponse.json({ error: message }, { status: 500 });
-  }
 }