### Godot version

4.1.1

### System information

linux

### Issue description

The `"%+f"` format adds a `+` sign in front of positive numbers. If you try to format `-0.0`, it breaks and displays both a `+` and a `-`.

### Steps to reproduce

```gdscript
@tool
extends EditorScript

func _run() -> void:
    print("%+f" % -0.0)
```

### Minimal reproduction project

see above
int sep = MAX(rfind("/"), rfind("\\"));
	if (sep == -1) {
		return *this;
	}
	return substr(sep + 1, length());
}
 ::get_extension() const {
	int pos = rfind(".");
	if (pos < 0 || pos < MAX(rfind("/"), rfind("\\"))) {
		return "";
	}
	return substr(pos + 1, length());
}
 ::path_join(const  &p_file) const {
	if (is_empty()) {
		return p_file;
	}
	if (operator[](length() - 1) == '/' || (p_file.size() > 0 && p_file.operator[](0) == '/')) {
		return *this + p_file;
	}
	return *this + "/" + p_file;
}
 ::property_name_encode() const {