Enable the StrictEffects flag

Author: gaearon

packages/shared/ReactFeatureFlags.js

@@ -25,7 +25,7 @@ export const debugRenderPhaseSideEffectsForStrictMode = __DEV__;
 
 // Helps identify code that is not safe for planned Offscreen API and Suspense semantics;
 // this feature flag only impacts StrictEffectsMode.
-export const enableStrictEffects = false;
+export const enableStrictEffects = true;
 
 // If TRUE, trees rendered with createRoot will be StrictEffectsMode.
 // If FALSE, these trees will be StrictLegacyMode.