[QA] "New dependencies version detected" toast persists after successfully updating via Loading Failed screen

### 🛠️ **Build version:**
Decentraland Creator Hub 0.45.0 (fix/bevy branch) — PR #1463

### 📔 **Issue Description:**
When opening a scene with outdated dependencies, the "Loading failed" screen correctly shows the friendly "This scene's dependencies are out of date and don't support the Bevy renderer. Update them to continue." message with an "Update Dependencies" action button. However, the separate "New dependencies version detected — UPDATE" toast (bottom of screen) remains visible throughout the entire flow — during the Loading Failed state, during "Installing dependencies...", and even after the scene finishes loading successfully alongside a "Scene dependencies were updated" confirmation toast. The original toast is never dismissed, even though clicking its own "UPDATE" action (or the Loading Failed screen's "Update Dependencies" button) is what triggers the update that resolves it.

### 👣 **STR:**
1. Open a scene with outdated dependencies (predating Bevy renderer support)
2. Observe the "Loading failed" screen with "Update Dependencies" button, plus a "New dependencies version detected — UPDATE" toast at the bottom
3. Click "Update Dependencies"
4. Observe "Installing dependencies..." screen — the toast from step 2 is still present
5. Wait for the scene to finish loading
6. Observe the scene loads successfully with a "Scene dependencies were updated" confirmation toast — but the original "New dependencies version detected" toast is still showing alongside it

### ✔️ **Expected Result:**
The "New dependencies version detected — UPDATE" toast should dismiss once the update is triggered (or once it completes), rather than persisting redundantly alongside the "Scene dependencies were updated" confirmation.

### ❌ **Actual Result with evidence:**
Toast persists across all three states — outdated-deps error screen, installing screen, and successful load — never dismissing on its own.
[Screenshots attached: Loading Failed screen, Installing dependencies screen, and loaded scene — all showing the persistent toast]

### ➗ **Reproduction:**
🔁 Always

#### 🖥️ **Operative system and additional Notes:**
Mac chip — M3.
Found while validating PR #1463, item "Outdated scene deps detection." Core fix (friendly message vs. raw CLI dump) works correctly — this is a follow-up polish issue on the notification lifecycle, not a regression of the fix itself.

https://github.com/user-attachments/assets/c2b7ac66-3a31-4802-8a2a-29a589d39c6d

https://github.com/user-attachments/assets/6e3f6962-e908-40e2-88ed-aa34929a596e