feat(container): update image app-template to v2.4.0 (#1079)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

bootstrap/templates/addons/discord-template-notifier/app/helmrelease.yaml.j2

@@ -8,7 +8,7 @@ spec:
   chart:
     spec:
       chart: app-template
-      version: 2.3.0
+      version: 2.4.0
       interval: 30m
       sourceRef:
         kind: HelmRepository

bootstrap/templates/addons/system-upgrade-controller/app/helmrelease.yaml.j2

@@ -8,7 +8,7 @@ spec:
   chart:
     spec:
       chart: app-template
-      version: 2.3.0
+      version: 2.4.0
       sourceRef:
         kind: HelmRepository
         name: bjw-s