Fix: [Script] doxygen_filter is very strict about DOXYGEN_API usage (#9351)

(cherry picked from commit ee5f23382d)

src/script/api/script_text.hpp

@@ -88,7 +88,7 @@ public:
 	 * @param ... Optional arguments for this string.
 	 */
 	ScriptText(StringID string, ...);
-#endif
+#endif /* DOXYGEN_API */
 	~ScriptText();
 
 #ifndef DOXYGEN_API