### 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
*this += ((const char32_t *)p_str);
#endif
	return *this;
}
 &::operator+=(const char32_t *p_str) {
	*this += (p_str);
	return *this;
}
 &::operator+=(char32_t p_char) {
	if (p_char == 0) {
		print_unicode_error("NUL character", true);
		return *this;
	}
	const int lhs_len = length();
	resize(lhs_len + 2);
	char32_t *dst = ptrw();
	if ((p_char & 0xfffff800) == 0xd800) {
		print_unicode_error(vformat("Unpaired surrogate (%x)", (uint32_t)p_char));
		dst[lhs_len] = _replacement_char;
	} else if (p_char > 0x10ffff) {
		print_unicode_error(vformat("Invalid unicode codepoint (%x)", (uint32_t)p_char));
		dst[lhs_len] = _replacement_char;
	} else {
		dst[lhs_len] = p_char;
	}
	dst[lhs_len + 1] = 0;
	return *this;
}
bool ::operator==(const char *p_str) const {