System Bridge - Set device class for binary sensor

[timmo001]

Proposed change

Sets device class for New Version Available binary sensor.

Continuation of #53892 (comment)

Type of change

• Code quality improvements to existing code or addition of tests

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

The integration reached or maintains the following Integration Quality Scale:

• 🥈 Silver

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[ludeeus]

Thanks! 👍