Use TEMPERATURE_DELTA for tplink temperature offset (#155239)

Co-authored-by: epenet <6771947+epenet@users.noreply.github.com>

homeassistant/components/tplink/number.py

@@ -10,6 +10,7 @@ from kasa import Device, Feature
 
 from homeassistant.components.number import (
     DOMAIN as NUMBER_DOMAIN,
+    NumberDeviceClass,
     NumberEntity,
     NumberEntityDescription,
     NumberMode,
@@ -56,6 +57,7 @@ NUMBER_DESCRIPTIONS: Final = (
     TPLinkNumberEntityDescription(
         key="temperature_offset",
         mode=NumberMode.BOX,
+        device_class=NumberDeviceClass.TEMPERATURE_DELTA,
     ),
     TPLinkNumberEntityDescription(
         key="pan_step",

tests/components/tplink/snapshots/test_number.ambr

@@ -347,7 +347,7 @@
     'name': None,
     'options': dict({
     }),
-    'original_device_class': None,
+    'original_device_class': <NumberDeviceClass.TEMPERATURE_DELTA: 'temperature_delta'>,
     'original_icon': None,
     'original_name': 'Temperature offset',
     'platform': 'tplink',
@@ -362,6 +362,7 @@
 # name: test_states[number.my_device_temperature_offset-state]
   StateSnapshot({
     'attributes': ReadOnlyDict({
+      'device_class': 'temperature_delta',
       'friendly_name': 'my_device Temperature offset',
       'max': 10,
       'min': -10,