style(components/ads): update EzoicPlaceholder styling

src/components/ads/ezoic-placeholder.tsx

@@ -42,7 +42,7 @@ export function EzoicPlaceholder({ id }: EzoicPlaceholderProps) {
   if (blocked) return null;
 
   return (
-    <div ref={containerRef} className="empty:hidden">
+    <div ref={containerRef} className="min-h-[250px]">
       <div id={`ezoic-pub-ad-placeholder-${id}`} />
     </div>
   );