chore(bind): return 413 status code when error is http.MaxBytesError (#4227)

* Bind: return 413 status code when error is `http.MaxBytesError`

The Go standard library includes a method `http.MaxBytesReader` that allows limiting the request body. For example, users can create a middleware like:

```go
func MiddlewareMaxBodySize(c *gin.Context) {
	// Limit request body to 100 bytes
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 100)
	c.Next()
}
```

When the body exceeds the limit, reading from the request body returns an error of type `http.MaxBytesError`.

This PR makes sure that when the error is of kind `http.MaxBytesError`, Gin returns the correct status code 413 (Request Entity Too Large) instead of a generic 400 (Bad Request).

* Disable test when using sonic

* Fix

* Disable for go-json too

* Add references to GitHub issues

* Test that the response is 400 for sonic and go-json

context.go

@@ -769,8 +769,19 @@ func (c *Context) BindUri(obj any) error {
 // It will abort the request with HTTP 400 if any error occurs.
 // See the binding package.
 func (c *Context) MustBindWith(obj any, b binding.Binding) error {
-	if err := c.ShouldBindWith(obj, b); err != nil {
-		c.AbortWithError(http.StatusBadRequest, err).SetType(ErrorTypeBind) //nolint: errcheck
+	err := c.ShouldBindWith(obj, b)
+	if err != nil {
+		var maxBytesErr *http.MaxBytesError
+
+		// Note: When using sonic or go-json as JSON encoder, they do not propagate the http.MaxBytesError error
+		// https://github.com/goccy/go-json/issues/485
+		// https://github.com/bytedance/sonic/issues/800
+		switch {
+		case errors.As(err, &maxBytesErr):
+			c.AbortWithError(http.StatusRequestEntityTooLarge, err).SetType(ErrorTypeBind) //nolint: errcheck
+		default:
+			c.AbortWithError(http.StatusBadRequest, err).SetType(ErrorTypeBind) //nolint: errcheck
+		}
 		return err
 	}
 	return nil