### 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)

memdelete(regex);
		}
		for (RegEx *regex : gdscript_signals_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : shaders_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : builtin_types_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : theme_override_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : csharp_function_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : csharp_properties_regexes) {
			memdelete(regex);
		}
		for (RegEx *regex : csharp_signal_regexes) {
			memdelete(regex);
		}
	}
};
ProjectConverter3To4::ProjectConverter3To4(int p_maximum_file_size_kb, int p_maximum_line_length) {
	maximum_file_size = p_maximum_file_size_kb * 1024;
	maximum_line_length = p_maximum_line_length;
}
bool ProjectConverter3To4::convert() {