### 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
aux = this->_camelcase_to_underscore().replace("_", " ").strip_edges();
	 cap;
	for (int i = 0; i < aux.get_slice_count(" "); i++) {
		 slice = aux.get_slicec(' ', i);
		if (slice.length() > 0) {
			slice[0] = _find_upper(slice[0]);
			if (i > 0) {
				cap += " ";
			}
			cap += slice;
		}
	}
	return cap;
}
 ::to_camel_case() const {
	 s = this->to_pascal_case();
	if (!s.is_empty()) {
		s[0] = _find_lower(s[0]);
	}
	return s;
}
 ::to_pascal_case() const {
	return this->capitalize().replace(" ", "");
}
 ::to_snake_case() const {