### 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)

changed_elements.append_array(check_for_rename_common(RenamesMap3To4::csharp_properties_renames, reg_container.csharp_properties_regexes, lines));
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::csharp_signals_renames, reg_container.csharp_signal_regexes, lines));
				changed_elements.append_array(check_for_rename_csharp_functions(lines, reg_container));
				changed_elements.append_array(check_for_rename_csharp_attributes(lines, reg_container));
				changed_elements.append_array(check_for_custom_rename(lines, "public class ", "public partial class "));
			} else if (file_name.ends_with(".gdshader") || file_name.ends_with(".shader")) {
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::shaders_renames, reg_container.shaders_regexes, lines));
			} else if (file_name.ends_with("tres")) {
				changed_elements.append_array(check_for_rename_classes(lines, reg_container));
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::shaders_renames, reg_container.shaders_regexes, lines));
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::builtin_types_renames, reg_container.builtin_types_regexes, lines));
				changed_elements.append_array(check_for_custom_rename(lines, "\\.shader", ".gdshader"));
			} else if (file_name.ends_with("project.godot")) {
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::project_godot_renames, reg_container.project_godot_regexes, lines));
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::builtin_types_renames, reg_container.builtin_types_regexes, lines));
				changed_elements.append_array(check_for_rename_input_map_scancode(lines, reg_container));
				changed_elements.append_array(check_for_rename_common(RenamesMap3To4::input_map_renames, reg_container.input_map_regexes, lines));
			} else if (file_name.ends_with(".csproj")) {
				
			} else {
				ERR_PRINT(vformat("\"%s\", is not supported!", file_name));
				continue;
			}
			for (String &line : lines) {
				if (uint64_t(line.length()) > maximum_line_length) {
					ignored_lines += 1;
				}
			}
		} else {
			reason.append(vformat("\tERROR: File has exceeded the maximum size allowed  - %d KB.", maximum_file_size / 1024));