feat: add code for network error

hrp/code/code.go

@@ -14,6 +14,7 @@ const (
 var (
 	ConfigureError     = errors.New("configure error")             // 3
 	UnauthorizedError  = errors.New("unauthorized error")          // 4
+	NetworkError       = errors.New("network error")               // 5
 	InvalidPython3Venv = errors.New("prepare python3 venv failed") // 9
 )
 
@@ -114,6 +115,7 @@ var errorsMap = map[error]int{
 	// environment
 	ConfigureError:     3,
 	UnauthorizedError:  4,
+	NetworkError:       5,
 	InvalidPython3Venv: 9,
 
 	// loader