### 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
} else {
		return false;
	}
}
static _FORCE_INLINE_ bool _is_valid_identifier_bit(int p_index, char32_t p_char) {
	if (p_index == 0 && is_digit(p_char)) {
		return false; // 
	}
	return is_ascii_identifier_char(p_char);
}
 ::validate_identifier() const {
	if (is_empty()) {
		return "_"; // 
	}
	 result = *this;
	int len = result.length();
	char32_t *buffer = result.ptrw();
	for (int i = 0; i < len; i++) {
		if (!_is_valid_identifier_bit(i, buffer[i])) {
			buffer[i] = '_';
		}
	}
	return result;
}
bool ::is_valid_identifier() const {
	int len = length();
	if (len == 0) {
		return false;
	}
	const char32_t *str = &operator[](0);