build: install Bleak by default on Linux

[terop]

As Bleak is soon to become the default adapter on Linux, install Bleak by default for the benefit of Linux users, both current and future. For future Bleak users this makes testing and adoption easier when the module is pre-installed.

[terop]

In case it is too early for this change it probably could remain open until a suitable time to merge this is available.

[ttu]

The plan is to make Bleak the default adapter for Linux in the next major release. For the current users, we aim to keep the amount of required dependencies to a minimum, so let's merge this when we make the switch to Bleak. I have created a new issue for the release and linked this PR to it.