### 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 = reg_container.reg_os_set_borderless.sub(line, "get_window().borderless = ($1)", true);
		// 
		line = reg_container.reg_os_get_borderless.sub(line, "get_window().borderless", true);
	}
	// 
	if (line.contains("OS.SCREEN_ORIENTATION_")) {
		line = reg_container.reg_os_screen_orient_enum.sub(line, "DisplayServer.SCREEN_$1", true);
	}
	// 
	if (line.contains("current_screen")) {
		line = reg_container.reg_os_current_screen.sub(line, "get_window().$1current_screen", true);
	}
	if (line.contains("min_window_size")) {
		line = reg_container.reg_os_min_window_size.sub(line, "get_window().$1min_size", true);
	}
	if (line.contains("max_window_size")) {
		line = reg_container.reg_os_max_window_size.sub(line, "get_window().$1max_size", true);
	}
	if (line.contains("window_position")) {
		line = reg_container.reg_os_window_position.sub(line, "get_window().$1position", true);
	}
	if (line.contains("window_size")) {
		line = reg_container.reg_os_window_size.sub(line, "get_window().$1size", true);
	}
	if (line.contains("et_screen_orientation")) {
		line = reg_container.reg_os_getset_screen_orient.sub(line, "DisplayServer.screen_$1et_orientation", true);
	}
	// 
	if (contains_function_call(line, "instance")) {