"Pending message" doesn't clear on correct timming

### Describe the bug

Found an issue where my Pending message is already consumed and the agent is thinking on it (I can read the thinking) but the message still has "(pending)" appended to it, thus misleading me.

### Affected version

GitHub Copilot CLI 1.0.75.

### Steps to reproduce the behavior

1. Ask tasks that need thinking while on medium or high thinking
2. Add additional prompts while it is still processing (you message is now pending)
3. Check the "Pending message" is appended
4. when the agent start thinking about your message, check the "Pending message" text is still present, although the message has already been delivered.

### Expected behavior

The "pending message" should clear before the agent starts thinking about the message, becaue by now it no longer is pending but was already delivered.

### Additional context

_No response_

Riproduci questo comportamento in GitHub Copilot CLI 1.0.75 inviando un prompt accodato durante un livello di ragionamento medio o alto, quindi osservalo quando l'agente inizia a elaborare quel prompt. Segui la visualizzazione del messaggio in sospeso durante la transizione da queued a delivered e considera conclusa la issue quando il testo “(pending)” scompare prima che l'agente inizi a ragionare sul messaggio.

Scritto dal modello di indicizzazione a partire dal testo della issue.