headers: Sync with upstream commit afdae67cc (4.0-alpha11)

godot-headers/godot/gdnative_interface.h

@@ -153,7 +153,7 @@ typedef enum {
 	GDNATIVE_CALL_ERROR_TOO_MANY_ARGUMENTS, /* expected is number of arguments */
 	GDNATIVE_CALL_ERROR_TOO_FEW_ARGUMENTS, /*  expected is number of arguments */
 	GDNATIVE_CALL_ERROR_INSTANCE_IS_NULL,
-
+	GDNATIVE_CALL_ERROR_METHOD_NOT_CONST, /* used for const call */
 } GDNativeCallErrorType;
 
 typedef struct {