### Godot version

4.0.2.stable

### System information

Ubuntu 22.10

### Issue description

This happens when converting a godot3 project to a godot4 project.
Godot3 source
```gdscript
extends Node2D

export(int) var integer := 2
export(Resource) var resource: Resource = null
```

Result
```gdscript
extends Node2D

@export var integer: int := 2
@export var resource: Resource: Resource = null
```

Expected result
```gdscript
extends Node2D

@export var integer := 2
@export var resource: Resource = null
```

If someone can point to where in the code this might be fixed maybe I can fix it myself, sounds like a good first issue.


### Steps to reproduce

Open the given project (or any project really) and convert it to a godot 4 project

### Minimal reproduction project

[Conversion Tool Typing Problem.zip](https://github.com/godotengine/godot/files/11185334/Conversion.Tool.Typing.Problem.zip)

}
	}
	{
		HashSet<String> all_functions;
		
		
		static const char *builtin_types_excluded_functions[] = { "dict_to_inst", "inst_to_dict", "bytes_to_var", "bytes_to_var_with_objects", "db_to_linear", "deg_to_rad", "linear_to_db", "rad_to_deg", "randf_range", "ped", "str_to_var", "var_to_str", "var_to_bytes", "var_to_bytes_with_objects", "move_toward", "uri_encode", "uri_decode", "remove_at", "get_rotation_quaternion", "limit_length", "grow_side", "is_absolute_path", "is_valid_int", "lerp", "to_ascii_buffer", "to_utf8_buffer", "to_utf32_buffer", "to_wchar_buffer", "ped", "remap", "rfind", nullptr };
		for (int current_index = 0; builtin_types_excluded_functions[current_index]; current_index++) {
			all_functions.insert(builtin_types_excluded_functions[current_index]);
		}
		
		
		
		
		
		
		
		
		
		List<StringName> classes_list;
		ClassDB::get_class_list(&classes_list);
		for (StringName &name_of_class : classes_list) {
			List<MethodInfo> method_list;
			ClassDB::get_method_list(name_of_class, &method_list, true);
			for (MethodInfo &function_data : method_list) {
				if (!all_functions.has(function_data.name)) {
					all_functions.insert(function_data.name);
				}
			}
		}