### 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)

line = line.replace("OS.GetWindowSafeArea()", "DisplayServer.ScreenGetUsableRect()");
	// 
	if (line.contains("GetTree().SetInputAsHandled()")) {
		line = line.replace("GetTree().SetInputAsHandled()", "GetViewport().SetInputAsHandled()");
	}
	// 
	// 
	if (line.contains("_UnhandledKeyInput(InputEventKey @event)")) {
		line = line.replace("_UnhandledKeyInput(InputEventKey @event)", "_UnhandledKeyInput(InputEvent @event)");
	}
	// 
	if (line.contains("Connect(")) {
		int start = line.find("Connect(");
		// 
		if (start == 0 || line.get(start - 1) != 's') {
			int end = get_end_parenthesis(line.substr(start)) + 1;
			if (end > -1) {
				Vector<String> parts = parse_arguments(line.substr(start, end));