YT-23469: Ensure proper destructor order inside |RunInFiberContext| even when exception is thrown

commit_hash:5dde84deb176c7a4be831d9870deab45f66d1237

Author: E1pp

yt/yt/core/concurrency/fiber_scheduler_thread.cpp

@@ -983,9 +983,13 @@ Y_NO_INLINE void RunInFiberContext(TFiber* fiber, TClosure callback)
 {
     TFiberSwitchHandler switchHandler(fiber);
     TNullPropagatingStorageGuard nullPropagatingStorageGuard;
+
+    auto cleanup = Finally([&callback] {
+        // To ensure callback is destroyed before switchHandler.
+        callback.Reset();
+    });
+
     callback();
-    // To ensure callback is destroyed before switchHandler.
-    callback.Reset();
 }
 
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