[DevTools] Fix memory leak when unmounting hoistables

Author: eps1lon

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

@@ -3669,6 +3669,6 @@ describe('Store', () => {
     `);
     style = document.head.querySelector('style');
     styleID = agent.getIDForHostInstance(style).id;
-    expect(store.containsElement(styleID)).toBe(false);
+    expect(store.containsElement(styleID)).toBe(true);
   });
 });

packages/react-devtools-shared/src/backend/fiber/renderer.js

@@ -991,8 +991,8 @@ function releaseHostResource(
         // eslint-disable-next-line no-for-of-loops/no-for-of-loops
         for (const firstInstance of resourceInstances) {
           publicInstanceToDevToolsInstanceMap.set(
+            publicInstance,
             firstInstance,
-            nearestInstance,
           );
           break;
         }