### 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 (got != expected) {
		ERR_PRINT(vformat("Failed to get proper data from get_object_of_execution. \"%s\" should return \"%s\"(%d), got \"%s\"(%d), instead.", base, expected, expected.size(), got, got.size()));
	}
	valid = valid && (got == expected);
}
{
	String line = "( )";
	Vector<String> got_vector = parse_arguments(line);
	String got = "";
	String expected = "";
	for (String &part : got_vector) {
		got += part + "|||";
	}
	if (got != expected) {
		ERR_PRINT(vformat("Failed to get proper data from parse_arguments. \"%s\" should return \"%s\"(%d), got \"%s\"(%d), instead.", line, expected, expected.size(), got, got.size()));
	}
	valid = valid && (got == expected);
}
{
	String line = "(a , b , c)";
	Vector<String> got_vector = parse_arguments(line);
	String got = "";
	String expected = "a|||b|||c|||";
	for (String &part : got_vector) {
		got += part + "|||";
	}
	if (got != expected) {
		ERR_PRINT(vformat("Failed to get proper data from parse_arguments. \"%s\" should return \"%s\"(%d), got \"%s\"(%d), instead.", line, expected, expected.size(), got, got.size()));
	}
	valid = valid && (got == expected);