Strengthen test assertions for configure_entity_ packed values

- Sensor and text_sensor device_class tests now extract and verify the
  packed argument is non-zero instead of just checking call presence
- Remove useless setup_test_environment fixture references in unit tests

tests/component_tests/sensor/test_sensor.py

@@ -1,5 +1,15 @@
 """Tests for the sensor component."""
 
+import re
+
+
+def _extract_packed_value(main_cpp, var_name):
+    """Extract the third (packed) argument from a configure_entity_ call."""
+    pattern = rf"{re.escape(var_name)}->configure_entity_\([^,]+,\s*\w+,\s*(\d+)\)"
+    match = re.search(pattern, main_cpp)
+    assert match, f"configure_entity_ call not found for {var_name}"
+    return int(match.group(1))
+
 
 def test_sensor_device_class_set(generate_main):
     """
@@ -10,5 +20,6 @@ def test_sensor_device_class_set(generate_main):
     # When
     main_cpp = generate_main("tests/component_tests/sensor/test_sensor.yaml")
 
-    # Then
-    assert "s_1->configure_entity_(" in main_cpp
+    # Then: device_class: voltage means packed value must be non-zero
+    packed = _extract_packed_value(main_cpp, "s_1")
+    assert packed != 0