### 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)

is_ignored = true;
		}
		uint64_t end_time = Time::get_singleton()->get_ticks_msec();
		String end_message = vformat("    Checking file took %10.3f ms.", (end_time - start_time) / 1000.0);
		if (ignored_lines != 0) {
			end_message += vformat(" Ignored %d lines, because their length exceeds maximum allowed characters - %d.", ignored_lines, maximum_line_length);
		}
		print_line(end_message);
		for (int k = 0; k < reason.size(); k++) {
			print_line(reason[k]);
		}
		if (changed_elements.size() > 0 && !is_ignored) {
			converted_files++;
			for (int k = 0; k < changed_elements.size(); k++) {
				print_line(String("\t\t") + changed_elements[k]);
			}
		}
	}
	print_line(vformat("Checking for valid conversion ended - all files(%d), files which would be converted(%d), files which would not be converted(%d).", collected_files.size(), converted_files, collected_files.size() - converted_files));
	uint64_t conversion_end_time = Time::get_singleton()->get_ticks_msec();
	print_line(vformat("Conversion of all files took %10.3f seconds.", (conversion_end_time - conversion_start_time) / 1000.0));
	return true;
}
Vector<String> ProjectConverter3To4::check_for_files() {
	Vector<String> collected_files = Vector<String>();
	Vector<String> directories_to_check = Vector<String>();
	directories_to_check.push_back("res://");
	while (!directories_to_check.is_empty()) {
		String path = directories_to_check.get(directories_to_check.size() - 1); 
		directories_to_check.resize(directories_to_check.size() - 1);