Add NextDNS system health (#74368)

Add system_health

homeassistant/components/nextdns/system_health.py

@@ -0,0 +1,25 @@
+"""Provide info to system health."""
+from __future__ import annotations
+
+from typing import Any
+
+from nextdns.const import API_ENDPOINT
+
+from homeassistant.components import system_health
+from homeassistant.core import HomeAssistant, callback
+
+
+@callback
+def async_register(  # pylint:disable=unused-argument
+    hass: HomeAssistant,
+    register: system_health.SystemHealthRegistration,
+) -> None:
+    """Register system health callbacks."""
+    register.async_register_info(system_health_info)
+
+
+async def system_health_info(hass: HomeAssistant) -> dict[str, Any]:
+    """Get info for the info page."""
+    return {
+        "can_reach_server": system_health.async_check_can_reach_url(hass, API_ENDPOINT)
+    }