Use MethodArgumentNotValidException for model attributes

Closes gh-29251

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ResponseEntityExceptionHandler.java

@@ -472,8 +472,11 @@ public abstract class ResponseEntityExceptionHandler implements MessageSourceAwa
 	 * @param request the current request
 	 * @return a {@code ResponseEntity} for the response to use, possibly
 	 * {@code null} when the response is already committed
+	 * @deprecated as of 6.0 since {@link org.springframework.web.method.annotation.ModelAttributeMethodProcessor}
+	 * now raises the {@link MethodArgumentNotValidException} subclass instead.
 	 */
 	@Nullable
+	@Deprecated(since = "6.0", forRemoval = true)
 	protected ResponseEntity<Object> handleBindException(
 			BindException ex, HttpHeaders headers, HttpStatusCode status, WebRequest request) {
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/support/DefaultHandlerExceptionResolver.java

@@ -574,7 +574,10 @@ public class DefaultHandlerExceptionResolver extends AbstractHandlerExceptionRes
 	 * @param handler the executed handler
 	 * @return an empty {@code ModelAndView} indicating the exception was handled
 	 * @throws IOException potentially thrown from {@link HttpServletResponse#sendError}
+	 * @deprecated as of 6.0 since {@link org.springframework.web.method.annotation.ModelAttributeMethodProcessor}
+	 * now raises the {@link MethodArgumentNotValidException} subclass instead.
 	 */
+	@Deprecated(since = "6.0", forRemoval = true)
 	protected ModelAndView handleBindException(BindException ex, HttpServletRequest request,
 			HttpServletResponse response, @Nullable Object handler) throws IOException {