How does React's useRef do to make it's return value ignore dependency warnings?

For example, consider the following code :

const useCustomRef = initialValue => useRef(initialValue);

const CustomComponent = () => {
  const ref1 = useRef();
  const ref2 = useCustomRef();

  useEffect(() => {
    ref2.current.otherRef = ref1.current;
  }, []);
  
  return <div>Ref test</div>;
};

(Note: Nevermind the silliness, here, this is only to make point.)

Now, importing (and rendering) this dummy component in an app running with react-scripts will print in the console :

path/to/dummy/component.jsx
Line 70:7:  React Hook useEffect has a missing dependency: 'ref2'. Either include it or remove the dependency array  react-hooks/exhaustive-deps

Is that warning built-in, or is it possible to specify a hooks' immutable properties?

For example, certain hooks return immutable and immutable properties, like :

const ref = useRef();                              // immutable
const handleCallback = useCallback(() => {}, []);  // mutable
const [ value, setValue ] = useState();            // mutable, immutable
const [ state, dispatch ] = useReducer(...);       // mutable, immutable
...

So, can a user-defined hook define the same properties so that they are not required as dependencies? I find it annoying to implement custom hooks returning immutable properties that are, then, required as dependencies while they would not otherwise (like for ref2 in the example above).