### 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)

int start = line.find("func ");
		start = line.substr(start).find("(") + start;
		int end = get_end_parenthesis(line.substr(start)) + 1;
		if (end > -1) {
			Vector<String> parts = parse_arguments(line.substr(start, end));
			String start_string = line.substr(0, start) + "(";
			for (int i = 0; i < parts.size(); i++) {
				start_string += parts[i].strip_edges().trim_prefix("var ");
				if (i != parts.size() - 1) {
					start_string += ", ";
				}
			}
			line = start_string + ")" + line.substr(end + start);
		}
	}
	// 
	if (contains_function_call(line, "yield(")) {
		int start = line.find("yield(");
		int end = get_end_parenthesis(line.substr(start)) + 1;
		if (end > -1) {
			Vector<String> parts = parse_arguments(line.substr(start, end));
			if (parts.size() == 2) {
				if (builtin) {
					line = line.substr(0, start) + "await " + parts[0] + "." + parts[1].replace("\\\"", "").replace("\\'", "").replace(" ", "") + line.substr(end + start);
				} else {
					line = line.substr(0, start) + "await " + parts[0] + "." + parts[1].replace("\"", "").replace("\'", "").replace(" ", "") + line.substr(end + start);
				}
			}
		}
	}