option to disable unread indicator in page/app title

### Your use case

#### What would you like to do?

opt-out of the behavior introduced in https://github.com/matrix-org/matrix-react-sdk/pull/10096

#### Why would you like to do it?

it's distracting me. I'm in rooms that by design are living their own life, like ones related to various projects.

I also know I'm not the only one.

#### How would you like to achieve it?

new option in preferences or appearance settings

### Have you considered any alternatives?

opt-in setting, removing behavior at all. opt-out seems the most reasonable though.

### Additional context

_No response_