Update victron_mqtt to 2026.4.7 (#349)

## Changes

- Skip devices with no visible metrics and no children from notifications

## Contributors

@tomer-w

Co-authored-by: tomer-w <57483589+tomer-w@users.noreply.github.com>

Author: github-actions[bot]

custom_components/victron_mqtt/manifest.json

@@ -10,7 +10,7 @@
   "iot_class": "local_push",
   "issue_tracker": "https://github.com/tomer-w/ha-victron-mqtt/issues",
   "requirements": [
-    "victron_mqtt==2026.4.6"
+    "victron_mqtt==2026.4.7"
   ],
   "ssdp": [
     {