### Godot version

v4.1.rc1.official [1f9e540f1]

### System information

Windows 10

### Issue description

Attempting to reorder the children of a TabContainer results in an unintended ordering and incorrect undo states.

Also happens in v4.0.3.stable.official [5222a99f5].

https://github.com/godotengine/godot/assets/3820082/2c2458e3-88ad-46d9-8a04-f289a049984a



### Steps to reproduce

1. Add a new TabContainer
2. Add a few children to it
3. Drag and drop to erroneously reorder them
4. Attempt to undo the change

### Minimal reproduction project

N/A
}
		if (!unique) {
			ERR_FAIL_COND(!node_hrcr_count.ref());
			
			
			uint32_t c = node_hrcr_count.get();
			String cn = p_child->get_class_name().operator String();
			const char32_t *cn_ptr = cn.ptr();
			uint32_t cn_length = cn.length();
			uint32_t c_chars = String::num_characters(c);
			uint32_t len = 2 + cn_length + c_chars;
			char32_t *str = (char32_t *)alloca(sizeof(char32_t) * (len + 1));
			uint32_t idx = 0;
			str[idx++] = '@';
			for (uint32_t i = 0; i < cn_length; i++) {
				str[idx++] = cn_ptr[i];
			}
			str[idx++] = '@';
			idx += c_chars;
			ERR_FAIL_COND(idx != len);
			str[idx] = 0;
			while (c) {
				str[--idx] = '0' + (c % 10);
				c /= 10;
			}
			p_child->data.name = String(str);
		}
	}
}
String increase_numeric_string(const String &s) {