### 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)

Vector<String> found_renames;
	int current_line = 1;
	for (String &line : lines) {
		if (uint64_t(line.length()) <= maximum_line_length) {
			for (unsigned int current_index = 0; current_index < cached_regexes.size(); current_index++) {
				if (line.contains(array[current_index][0])) {
					TypedArray<RegExMatch> reg_match = cached_regexes[current_index]->search_all(line);
					if (reg_match.size() > 0) {
						found_renames.append(line_formatter(current_line, array[current_index][0], array[current_index][1], line));
					}
				}
			}
		}
		current_line++;
	}
	return found_renames;
}
// Prints full info about renamed things e.g.:
// Line (67) remove -> remove_at  -  LINE """ doubler._blacklist.remove(0) """
String ProjectConverter3To4::line_formatter(int current_line, String from, String to, String line) {