https://github.com/knative-extensions/eventing-github/blob/f34a508f89e52fe4ebd5eba5f630a0ae07d923cb/pkg/reconciler/source/githubsource.go#L168-L209

finalizekind.go

func (r *Reconciler) FinalizeKind(ctx context.Context, source *sourcesv1alpha1.GitHubSource) pkgreconciler.Event {
	// If a webhook was created, try to delete it
	if source.Status.WebhookIDKey != "" {
		// Get access token
		accessToken, err := r.secretFrom(ctx, source.Namespace, source.Spec.AccessToken.SecretKeyRef)
		if apierrors.IsNotFound(err) {
			source.Status.MarkNoSecrets("AccessTokenNotFound", "%s", err)
			controller.GetEventRecorder(ctx).Eventf(source, corev1.EventTypeWarning,
				"WebhookDeletionSkipped", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
			// return EventTypeNormal to avoid finalize loop
			return pkgreconciler.NewEvent(corev1.EventTypeNormal, "WebhookDeletionSkipped", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
		} else if err != nil {
			controller.GetEventRecorder(ctx).Eventf(source, corev1.EventTypeWarning,
				"WebhookDeletionFailed", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
			return fmt.Errorf("error getting secret: %v", err)
		}

		args := &webhookArgs{
			source:                source,
			accessToken:           accessToken,
			alternateGitHubAPIURL: source.Spec.GitHubAPIURL,
			hookID:                source.Status.WebhookIDKey,
		}
		// Delete the webhook using the access token and stored webhook ID
		err = r.deleteWebhook(ctx, args)
		var gherr *ghclient.ErrorResponse
		if errors.As(err, &gherr) {
			if gherr.Response.StatusCode == http.StatusNotFound {
				controller.GetEventRecorder(ctx).Eventf(source, corev1.EventTypeWarning, "WebhookDeletionSkipped", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
				// return EventTypeNormal to avoid finalize loop
				return pkgreconciler.NewEvent(corev1.EventTypeNormal, "WebhookDeletionSkipped", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
			}
		} else {
			controller.GetEventRecorder(ctx).Eventf(source, corev1.EventTypeWarning,
				"WebhookDeletionFailed", "Could not delete webhook %q: %v", source.Status.WebhookIDKey, err)
			return fmt.Errorf("error deleting webhook: %v", err)
		}
		// Webhook deleted, clear ID
		source.Status.WebhookIDKey = ""
	}
	return nil
}