Rename api_key.deleted event type to api_key.revoked (#1476)

## Description

The SDK currently defines the API key event type as `api_key.deleted`,
but the actual WorkOS API expects `api_key.revoked`. This mismatch
causes a 400 error when passing `api_key.deleted` to `listEvents()`:

```
GenericServerException: Invalid name parameter, received: 'api_key.deleted'. You must pass in valid event names
```

The [WorkOS Events documentation](https://workos.com/docs/events) lists
this event as **"API key revoked event"** with the type
`api_key.revoked`.

### Changes

**`src/common/interfaces/event.interface.ts`**
- `ApiKeyDeletedEvent` → `ApiKeyRevokedEvent`
- `ApiKeyDeletedEventResponse` → `ApiKeyRevokedEventResponse`
- Event literal `'api_key.deleted'` → `'api_key.revoked'`
- Updated `Event` and `EventResponse` union types

**`src/common/serializers/event.serializer.ts`**
- Deserialisation case `'api_key.deleted'` → `'api_key.revoked'`

This is consistent with other revocable resources in the SDK that
already use `revoked` (e.g. `invitation.revoked`, `session.revoked`).

Closes #1475

## Documentation

Does this require changes to the WorkOS Docs? E.g. the [API
Reference](https://workos.com/docs/reference) or code snippets need
updates.

- [ ] Yes

The [Events documentation](https://workos.com/docs/events) already lists
the correct event name `api_key.revoked`. No documentation changes are
required.