Update CSS selector for extracting titles in DuckDuckGo parser

Replaced the overly complex CSS selector with a simplified "h2" selector for extracting titles. This change improves maintainability and ensures accurate title extraction from the updated DOM structure.

sites/duckduckgo/duckduckgo.go

@@ -105,7 +105,7 @@ func (c Config) Search(ctx context.Context, b extractor.Browser, query string) (
 			return fmt.Errorf("failed to get link: %w", err)
 		}
 
-		titles := n.Select("div:nth-child(2) > div:nth-child(1) > div:nth-child(2) > p:nth-child(1)")
+		titles := n.Select("h2")
 
 		if len(titles) != 0 {
 			r.Title, _ = titles[0].Text()