### Godot version

4.0 RC1

### System information

Linux Mint 20.3 Cinnamon

### Issue description

Tried converting a 3.5 game to 4.0 RC1. The conversion popup menu closed after a few seconds, and trying to edit the game crashes the entire engine with the following errors, which seem to be related to one music file not loading:
![errors](https://user-images.githubusercontent.com/125468288/219127087-f5a78035-4e4a-4625-aadb-e0cde6d5ac3d.png)

Not sure what's causing the issue, because when I created a new project with only that file and converted it I didn't get these errors, but consistently get them when trying to convert that game.

### Steps to reproduce

- Download the reproduction project below
- Import in Godot 4.0, and click "convert full project"
- If the bug happens, the engine will crash whenever trying to edit or run the converted project

### Minimal reproduction project

[Music Convertor Crash Demo.zip](https://github.com/godotengine/godot/files/10746591/Music.Convertor.Crash.Demo.zip)

}
		}
		current_line++;
	}
	return found_renames;
}
void ProjectConverter3To4::rename_input_map_scancode(Vector<SourceLine> &source_lines, const RegExContainer &reg_container) {
	// 
	const int old_spkey = (1 << 24);
	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) {
			TypedArray<RegExMatch> reg_match = reg_container.input_map_keycode.search_all(line);
			for (int i = 0; i < reg_match.size(); ++i) {
				Ref<RegExMatch> match = reg_match[i];
				PackedStringArray strings = match->get_strings();
				int key = strings[3].to_int();
				if (key & old_spkey) {
					// 
					key = (key & ~old_spkey) | (int)Key::SPECIAL;
					line = line.replace(strings[0], String(",\"") + strings[1] + "scancode\":" + String::num_int64(key));
				}
			}
		}
	}
}
void ProjectConverter3To4::rename_joypad_buttons_and_axes(Vector<SourceLine> &source_lines, const RegExContainer &reg_container) {