Make it a policy to never show Labs when `"show_labs_settings": false`

### Your use case

#### What would you like to do?
**Never** show the Labs tab in settings unless `show_labs_settings` is enabled.

#### Why would you like to do it?
It's extremely confusing for users that the Labs tab appears but only has one or two features in it. Many people in `#element-web:matrix.org` have been confused by this.

#### How would you like to achieve it?
If a feature is in beta but we want to allow more people to try it, then it should come out of the Labs tab and be placed elsewhere in settings.

### Have you considered any alternatives?

https://github.com/vector-im/element-web/issues/8498

or

Show all of the Labs settings but have them disabled with a sentence saying these are only available when `show_labs_settings` is enabled.

### Additional context

_No response_