We don't actually use this anywhere, so let's remove it.

https://github.com/facebook/react/blob/f1d00156df5453bc62bd5668fefdcac4ca67e90e/src/renderers/shared/fiber/ReactFiberScheduler.js#L1504-L1512
performWithPriority(priorityLevel: PriorityLevel, fn: Function): void,
  batchedUpdates<A>(fn: () => A): A,
  unbatchedUpdates<A>(fn: () => A): A,
  flushSync<A>(fn: () => A): A,
  deferredUpdates<A>(fn: () => A): A,
  
  getPublicRootInstance(
    container: OpaqueRoot,
  ): React$Component<any, any> | TI | I | null,
  
  findHostInstance(component: Fiber): I | TI | null,
  
  findHostInstanceWithNoPortals(component: Fiber): I | TI | null,
};
getContextForSubtree._injectFiber(function(fiber: Fiber) {
  const parentContext = findCurrentUnmaskedContext(fiber);
  return isContextProvider(fiber)
    ? processChildContext(fiber, parentContext, false)
    : parentContext;
});
module.exports = function<T, P, I, TI, PI, C, CX, PL>(
  config: HostConfig<T, P, I, TI, PI, C, CX, PL>,
): Reconciler<C, I, TI> {
  var {getPublicInstance} = config;
  var {
    scheduleUpdate,
    getPriorityContext,
    performWithPriority,
    batchedUpdates,
    unbatchedUpdates,