[be] Remove unshipped experimental <Cache> element type (facebook#28698)

Removes the `<Cache />` element type since we're going with a simpler
caching strategy.

Author: josephsavona

packages/react-devtools-shared/src/__tests__/store-test.js

@@ -1575,7 +1575,6 @@ describe('Store', () => {
         <FakeHigherOrderComponent />
         <MemoizedFakeHigherOrderComponent />
         <ForwardRefFakeHigherOrderComponent />
-        <React.unstable_Cache />
         <MemoizedFakeHigherOrderComponentWithDisplayNameOverride />
         <ForwardRefFakeHigherOrderComponentWithDisplayNameOverride />
       </React.Fragment>
@@ -1603,7 +1602,6 @@ describe('Store', () => {
             <Baz> [withFoo][withBar]
             <Baz> [Memo][withFoo][withBar]
             <Baz> [ForwardRef][withFoo][withBar]
-            <Cache>
             <memoRefOverride>
             <forwardRefOverride>
     `);

packages/react-devtools-shell/src/app/ElementTypes/index.js

@@ -18,7 +18,6 @@ import {
   Profiler,
   StrictMode,
   Suspense,
-  unstable_Cache as Cache,
 } from 'react';
 
 const Context = createContext('abc');

packages/react-reconciler/src/ReactFiber.js

@@ -28,7 +28,6 @@ import {
   isHostSingletonType,
 } from './ReactFiberConfig';
 import {
-  enableCache,
   enableProfilerTimer,
   enableScopeAPI,
   enableLegacyHidden,
@@ -66,7 +65,6 @@ import {
   ScopeComponent,
   OffscreenComponent,
   LegacyHiddenComponent,
-  CacheComponent,
   TracingMarkerComponent,
 } from './ReactWorkTags';
 import {OffscreenVisible} from './ReactFiberActivityComponent';
@@ -104,7 +102,6 @@ import {
   REACT_SCOPE_TYPE,
   REACT_OFFSCREEN_TYPE,
   REACT_LEGACY_HIDDEN_TYPE,
-  REACT_CACHE_TYPE,
   REACT_TRACING_MARKER_TYPE,
 } from 'shared/ReactSymbols';
 import {TransitionTracingMarker} from './ReactFiberTracingMarkerComponent';
@@ -560,11 +557,6 @@ export function createFiberFromTypeAndProps(
           return createFiberFromScope(type, pendingProps, mode, lanes, key);
         }
       // Fall through
-      case REACT_CACHE_TYPE:
-        if (enableCache) {
-          return createFiberFromCache(pendingProps, mode, lanes, key);
-        }
-      // Fall through
       case REACT_TRACING_MARKER_TYPE:
         if (enableTransitionTracing) {
           return createFiberFromTracingMarker(pendingProps, mode, lanes, key);
@@ -807,18 +799,6 @@ export function createFiberFromLegacyHidden(
   return fiber;
 }
 
-export function createFiberFromCache(
-  pendingProps: any,
-  mode: TypeOfMode,
-  lanes: Lanes,
-  key: null | string,
-): Fiber {
-  const fiber = createFiber(CacheComponent, pendingProps, key, mode);
-  fiber.elementType = REACT_CACHE_TYPE;
-  fiber.lanes = lanes;
-  return fiber;
-}
-
 export function createFiberFromTracingMarker(
   pendingProps: any,
   mode: TypeOfMode,