Hardcode disableIEWorkarounds for www (#28811)

This has landed and is true everywhere, but let's keep the flag until it
lands in the stable release.

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -13,7 +13,6 @@
 // Use __VARIANT__ to simulate a GK. The tests will be run twice: once
 // with the __VARIANT__ set to `true`, and once set to `false`.
 
-export const disableIEWorkarounds = __VARIANT__;
 export const disableSchedulerTimeoutInWorkLoop = __VARIANT__;
 export const enableLazyContextPropagation = __VARIANT__;
 export const forceConcurrentByDefaultForTesting = __VARIANT__;

packages/shared/forks/ReactFeatureFlags.www.js

@@ -15,7 +15,6 @@ import typeof * as DynamicFeatureFlags from './ReactFeatureFlags.www-dynamic';
 const dynamicFeatureFlags: DynamicFeatureFlags = require('ReactFeatureFlags');
 
 export const {
-  disableIEWorkarounds,
   enableTrustedTypesIntegration,
   enableDebugTracing,
   enableLazyContextPropagation,
@@ -49,6 +48,7 @@ export const enableUpdaterTracking = __PROFILE__;
 export const enableSuspenseAvoidThisFallback = true;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 
+export const disableIEWorkarounds = true;
 export const enableCPUSuspense = true;
 export const enableUseMemoCacheHook = true;
 export const enableUseEffectEventHook = true;

scripts/jest/setupTests.www.js

@@ -15,6 +15,11 @@ jest.mock('shared/ReactFeatureFlags', () => {
   // code live.
   actual.disableInputAttributeSyncing = __VARIANT__;
 
+  // This is hardcoded to true for the next release,
+  // but still run the tests against both variants until
+  // we remove the flag.
+  actual.disableIEWorkarounds = __VARIANT__;
+
   return actual;
 });