### 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)

if (line.contains("OS.get_screen_count")) {
		line = line.replace("OS.get_screen_count", "DisplayServer.get_screen_count");
	}
	if (line.contains("OS.get_screen_dpi")) {
		line = line.replace("OS.get_screen_dpi", "DisplayServer.screen_get_dpi");
	}
	if (line.contains("OS.get_screen_max_scale")) {
		line = line.replace("OS.get_screen_max_scale", "DisplayServer.screen_get_max_scale");
	}
	if (line.contains("OS.get_screen_position")) {
		line = line.replace("OS.get_screen_position", "DisplayServer.screen_get_position");
	}
	if (line.contains("OS.get_screen_refresh_rate")) {
		line = line.replace("OS.get_screen_refresh_rate", "DisplayServer.screen_get_refresh_rate");
	}
	if (line.contains("OS.get_screen_scale")) {
		line = line.replace("OS.get_screen_scale", "DisplayServer.screen_get_scale");
	}
	if (line.contains("OS.get_screen_size")) {
		line = line.replace("OS.get_screen_size", "DisplayServer.screen_get_size");
	}
	if (line.contains("OS.set_icon")) {
		line = line.replace("OS.set_icon", "DisplayServer.set_icon");
	}
	if (line.contains("OS.set_native_icon")) {
		line = line.replace("OS.set_native_icon", "DisplayServer.set_native_icon");
	}
	// 
	if (line.contains("OS.window_borderless")) {
		line = line.replace("OS.window_borderless", "get_window().borderless");