Update set_temperature_offset-related test-code

Author: bouwew

tests/test_smile.py

@@ -661,8 +661,13 @@ async def tinker_temp_offset(smile, dev_id):
         """Change temperature_offset to test functionality."""
         new_offset = 1.0
         _LOGGER.info("- Adjusting temperature offset to %s", new_offset)
-        await smile.set_temperature_offset("dummy", dev_id, new_offset)
-        _LOGGER.info("  + worked as intended")
+        try:
+            await smile.set_temperature_offset("dummy", dev_id, new_offset)
+            _LOGGER.info("  + worked as intended")
+            return True
+        except pw_exceptions.PlugwiseError:
+            _LOGGER.info("  + failed as intended")
+            return False
 
     @pytest.mark.asyncio
     async def test_connect_legacy_anna(self):
@@ -1446,7 +1451,14 @@ async def test_connect_anna_without_boiler_fw42(self):
             smile, "c34c6864216446528e95d88985e714cc", good_schedules=["Normal"]
         )
         assert result
-        await self.tinker_temp_offset(smile, "7ffbb3ab4b6c4ab2915d7510f7bf8fe9")
+        result = await self.tinker_temp_offset(
+            smile, "7ffbb3ab4b6c4ab2915d7510f7bf8fe9"
+        )
+        assert result
+        result = await self.tinker_temp_offset(
+            smile, "a270735e4ccd45239424badc0578a2b1"
+        )
+        assert not result
         await smile.close_connection()
         await self.disconnect(server, client)