Replace Entity.device_state_attributes with Entity.extra_state_attributes

[ReneNulschDE]

With HA 2021.12, Entity.device_state_attributes is deprecated and the following warning is shown in the log:

2021-11-22 08:27:56 WARNING (MainThread) [homeassistant.helpers.entity] Entity sensor.washing_machine_status (<class 'custom_components.miele.sensor.MieleStatusSensor'>) implements device_state_attributes. Please report it to the custom component author.
2021-11-22 08:28:01 WARNING (MainThread) [homeassistant.helpers.entity] Entity miele.washing_machine (<class 'custom_components.miele.MieleDevice'>) implements device_state_attributes. Please report it to the custom component author.

The PR will replace Entity.device_state_attributes with Entity.extra_state_attributes.

[gigatexel]

@ReneNulschDE is the developer maintaining this repository still active?

[kloknibor]

@gigatexel I am still here. I have just been swamped and been abroad for work a lot lately. Since this is just a opensource project without profit it is not my biggest priority. So my apologies that updates are a bit slow. I'll try to check this PR this week.

[gigatexel]

thanks for all you effort, really!