fix: add missing isApifyIntegration field to Webhook type (#523)

This PR adds a missing field on the `Webhook` interface. As per the
[documentation](https://docs.apify.com/platform/integrations/actors/integrating-actors-via-api),
one can programmatically integrate actors together using the "create
webhook" endpoint. The `isApifyIntegration` field helps the UI
distinguish whether to render it as an ordinary HTTP webhook in the
Apify console.

---------

Co-authored-by: Martin Adámek <[email protected]>
Co-authored-by: Josef Válek <[email protected]>

src/resource_clients/webhook.ts

@@ -93,6 +93,7 @@ export interface Webhook {
     lastDispatch: string;
     stats: WebhookStats;
     shouldInterpolateStrings: boolean;
+    isApifyIntegration?: boolean;
     headersTemplate?: string;
     description?: string;
 }
@@ -112,6 +113,7 @@ export type WebhookUpdateData = Partial<
         | 'requestUrl'
         | 'payloadTemplate'
         | 'shouldInterpolateStrings'
+        | 'isApifyIntegration'
         | 'headersTemplate'
         | 'description'
     >