fix(connector): make webhook source verification mandatory for adyen (#2360)

crates/router/src/core/webhooks.rs

@@ -895,6 +895,10 @@ pub async fn webhooks_core<W: types::OutgoingWebhookType>(
                     merchant_account.merchant_id.clone(),
                 )],
             );
+        } else if connector.is_webhook_source_verification_mandatory() {
+            // if webhook consumption is mandatory for connector, fail webhook
+            // so that merchant can retrigger it after updating merchant_secret
+            return Err(errors::ApiErrorResponse::WebhookAuthenticationFailed.into());
         }
 
         logger::info!(source_verified=?source_verified);