### 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)

}
		}
		previous_character = character;
	}
	Vector<String> clean_parts;
	for (String &part : parts) {
		part = part.strip_edges();
		if (!part.is_empty()) {
			clean_parts.append(part);
		}
	}
	return clean_parts;
}
int ProjectConverter3To4::get_end_parenthesis(const String &line) const {
	int current_state = 0;
	for (int current_index = 0; line.length() > current_index; current_index++) {
		char32_t character = line.get(current_index);
		if (character == '(') {
			current_state++;
		}
		if (character == ')') {
			current_state--;
			if (current_state == 0) {
				return current_index;
			}
		}
	}
	return -1;
}
String ProjectConverter3To4::connect_arguments(const Vector<String> &arguments, int from, int to) const {