Fix deprecated device_registry.async_get_device call

async_get_device() is deprecated (removal targeted for 2027.8.0) because
device identifiers are no longer guaranteed unique across config entries.
Home Assistant logs a deprecation warning on every sw_version update:

  Detected that custom integration 'solis_modbus' calls
  device_registry.async_get_device, which is deprecated because device
  identifiers and connections are no longer unique across config entries

Switch to the non-deprecated async_get_devices() (plural), which performs
the same identifiers-based lookup without the ambiguity concern, and take
the first match to preserve the existing single-device behavior.

Author: tuckshoprn

custom_components/solis_modbus/sensors/solis_derived_sensor.py

@@ -210,7 +210,7 @@ def _update_device_sw_version(self, protocol_version) -> None:
         if not serial:
             return
         dev_reg = dr.async_get(self.hass)
-        device = dev_reg.async_get_device(identifiers={(DOMAIN, serial)})
+        device = next(iter(dev_reg.async_get_devices(identifiers={(DOMAIN, serial)})), None)
         sw_version = f"Protocol {protocol_version}"
         if device and device.sw_version != sw_version:
             dev_reg.async_update_device(device.id, sw_version=sw_version)