Add product calculation to Group sensor (#87373)

* Group product

* config flow

tests/components/group/test_sensor.py

@@ -1,6 +1,7 @@
 """The tests for the Group Sensor platform."""
 from __future__ import annotations
 
+from math import prod
 import statistics
 from typing import Any
 from unittest.mock import patch
@@ -45,6 +46,7 @@ MEAN = statistics.mean(VALUES)
 MEDIAN = statistics.median(VALUES)
 RANGE = max(VALUES) - min(VALUES)
 SUM_VALUE = sum(VALUES)
+PRODUCT_VALUE = prod(VALUES)
 
 
 @pytest.mark.parametrize(
@@ -57,6 +59,7 @@ SUM_VALUE = sum(VALUES)
         ("last", VALUES[2], {ATTR_LAST_ENTITY_ID: "sensor.test_3"}),
         ("range", RANGE, {}),
         ("sum", SUM_VALUE, {}),
+        ("product", PRODUCT_VALUE, {}),
     ],
 )
 async def test_sensors(