[Glitch] React Strict Mode

Port c47922602ff43562ebe687bcbef23d43b301b18f to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/ui/util/intersection_observer_wrapper.js

@@ -25,7 +25,7 @@ class IntersectionObserverWrapper {
     this.observerBacklog.forEach(([ id, node, callback ]) => {
       this.observe(id, node, callback);
     });
-    this.observerBacklog = null;
+    this.observerBacklog = [];
   }
 
   observe (id, node, callback) {

app/javascript/flavours/glitch/main.tsx

@@ -1,3 +1,4 @@
+import { StrictMode } from 'react';
 import { createRoot } from 'react-dom/client';
 
 import { Globals } from '@react-spring/web';
@@ -33,7 +34,11 @@ function main() {
     await initializeEmoji();
 
     const root = createRoot(mountNode);
-    root.render(<Mastodon {...props} />);
+    root.render(
+      <StrictMode>
+        <Mastodon {...props} />
+      </StrictMode>,
+    );
     store.dispatch(setupBrowserNotifications());
 
     if (isProduction() && me && 'serviceWorker' in navigator) {