chore(deps): update dependency alert to notification.toolkit.fluxcd.i…

…o/v1beta3

| datasource     | package | from                                   | to                                     |
| -------------- | ------- | -------------------------------------- | -------------------------------------- |
| kubernetes-api | Alert   | notification.toolkit.fluxcd.io/v1beta2 | notification.toolkit.fluxcd.io/v1beta3 |

kubernetes/main/apps/flux-system/add-ons/notification/discord.yaml

@@ -11,7 +11,7 @@ spec:
     name: discord-secrets
 ---
 # yaml-language-server: $schema=https://kubernetes-schemas.zinn.ca/notification.toolkit.fluxcd.io/alert_v1beta2.json
-apiVersion: notification.toolkit.fluxcd.io/v1beta2
+apiVersion: notification.toolkit.fluxcd.io/v1beta3
 kind: Alert
 metadata:
   name: cluster-alert