### 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 len = 0;
	const char *aux = p_str;
	while (*(aux++) != 0) {
		len++;
	}
	if (length() != len) {
		return false;
	}
	if (is_empty()) {
		return true;
	}
	int l = length();
	const char32_t *dst = get_data();
	
	for (int i = 0; i < l; i++) {
		if ((char32_t)p_str[i] != dst[i]) {
			return false;
		}
	}
	return true;
}
bool ::operator==(const wchar_t *p_str) const {