## React version
React version: 18.3.0-next-b0671f9ea-20230130

## Problem
In `StrictMode`,  when using hydrateRoot to render a component that using `useSyncExternalStore` it seems that useSES will do hydration twice. 

But in second hydration process,  useSES does not use the result of `getServerSnapshot` as initial state, which will cause hydration error.

This problem will only happen in `development` mode, 

## Reproduce
Link to code example:
https://codesandbox.io/s/useses-18-3-rojznv

It works well in react 18.2
https://codesandbox.io/s/useses-18-2-13iskc




getSnapshot,
      setSnapshot: (null: any),
    },
    source,
    subscribe,
  }: MutableSourceMemoizedState<Source, Snapshot>);
  return useMutableSource(hook, source, getSnapshot, subscribe);
}
function updateMutableSource<Source, Snapshot>(
  source: MutableSource<Source>,
  getSnapshot: MutableSourceGetSnapshotFn<Source, Snapshot>,
  subscribe: MutableSourceSubscribeFn<Source, Snapshot>,
): Snapshot {
  if (!enableUseMutableSource) {
    return (undefined: any);
  }
  const hook = updateWorkInProgressHook();
  return useMutableSource(hook, source, getSnapshot, subscribe);
}
function mountSyncExternalStore<T>(
  subscribe: (() => void) => () => void,
  getSnapshot: () => T,
  getServerSnapshot?: () => T,
): T {
  const fiber = currentlyRenderingFiber;
  const hook = mountWorkInProgressHook();
  let nextSnapshot;
  const isHydrating = getIsHydrating();
  if (isHydrating) {
    if (getServerSnapshot === undefined) {