### 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)

static String error_message = "The master and mastersync rpc behavior is not officially supported anymore. Try using another keyword or making custom logic using Multiplayer.GetRemoteSenderId()\n";
	for (SourceLine &source_line : source_lines) {
		if (source_line.is_comment) {
			continue;
		}
		String &line = source_line.line;
		if (uint64_t(line.length()) <= maximum_line_length) {
			line = reg_container.keyword_csharp_remote.sub(line, "[RPC(MultiplayerAPI.RPCMode.AnyPeer)]", true);
			line = reg_container.keyword_csharp_remotesync.sub(line, "[RPC(MultiplayerAPI.RPCMode.AnyPeer, CallLocal = true)]", true);
			line = reg_container.keyword_csharp_puppet.sub(line, "[RPC]", true);
			line = reg_container.keyword_csharp_puppetsync.sub(line, "[RPC(CallLocal = true)]", true);
			line = reg_container.keyword_csharp_master.sub(line, error_message + "[RPC]", true);
			line = reg_container.keyword_csharp_mastersync.sub(line, error_message + "[RPC(CallLocal = true)]", true);
		}
	}
}
Vector<String> ProjectConverter3To4::check_for_rename_csharp_attributes(Vector<String> &lines, const RegExContainer &reg_container) {
	int current_line = 1;
	Vector<String> found_renames;
	for (String &line : lines) {
		if (uint64_t(line.length()) <= maximum_line_length) {
			String old;
			old = line;
			line = reg_container.keyword_csharp_remote.sub(line, "[RPC(MultiplayerAPI.RPCMode.AnyPeer)]", true);
			if (old != line) {
				found_renames.append(line_formatter(current_line, "[Remote]", "[RPC(MultiplayerAPI.RPCMode.AnyPeer)]", line));
			}
			old = line;