### 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)

public:
	
	RegEx reg_is_empty = RegEx("\\bempty\\(");
	RegEx reg_super = RegEx("([\t ])\\.([a-zA-Z_])");
	RegEx reg_json_to = RegEx("\\bto_json\\b");
	RegEx reg_json_parse = RegEx("([\t ]{0,})([^\n]+)parse_json\\(([^\n]+)");
	RegEx reg_json_non_new = RegEx("([\t ]{0,})([^\n]+)JSON\\.parse\\(([^\n]+)");
	RegEx reg_json_print = RegEx("\\bJSON\\b\\.print\\(");
	RegEx reg_export = RegEx("export\\(([a-zA-Z0-9_]+)\\)[ ]+var[ ]+([a-zA-Z0-9_]+)");
	RegEx reg_export_advanced = RegEx("export\\(([^)^\n]+)\\)[ ]+var[ ]+([a-zA-Z0-9_]+)([^\n]+)");
	RegEx reg_setget_setget = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+([a-zA-Z0-9_]+)[ \t]*,[ \t]*([a-zA-Z0-9_]+)");
	RegEx reg_setget_set = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+([a-zA-Z0-9_]+)[ \t]*[,]*[^\n]*$");
	RegEx reg_setget_get = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+,[ \t]*([a-zA-Z0-9_]+)[ \t]*$");
	RegEx reg_join = RegEx("([\\(\\)a-zA-Z0-9_]+)\\.join\\(([^\n^\\)]+)\\)");
	RegEx reg_image_lock = RegEx("([a-zA-Z0-9_\\.]+)\\.lock\\(\\)");
	RegEx reg_image_unlock = RegEx("([a-zA-Z0-9_\\.]+)\\.unlock\\(\\)");
	RegEx reg_instantiate = RegEx("\\.instance\\(([^\\)]*)\\)");
	
	RegEx reg_os_current_screen = RegEx("\\bOS\\.((set_|get_)?)current_screen\\b");
	RegEx reg_os_min_window_size = RegEx("\\bOS\\.((set_|get_)?)min_window_size\\b");
	RegEx reg_os_max_window_size = RegEx("\\bOS\\.((set_|get_)?)max_window_size\\b");
	RegEx reg_os_window_position = RegEx("\\bOS\\.((set_|get_)?)window_position\\b");
	RegEx reg_os_window_size = RegEx("\\bOS\\.((set_|get_)?)window_size\\b");
	RegEx reg_os_getset_screen_orient = RegEx("\\bOS\\.(s|g)et_screen_orientation\\b");
	
	RegEx reg_os_set_window_resizable = RegEx(make_regex_gds_os_property_set("set_window_resizable"));
	RegEx reg_os_assign_window_resizable = RegEx(make_regex_gds_os_property_assign("window_resizable"));