ostree plugin's presence in BuildStream core is painful when developing buildstream on platforms without ostree
Background
There are a number of pain points experienced by anyone developing BuildStream on a platform on which ostree is not available.
- We don't have a way in our testing setup to not install all the python dependencies of the core plugins. This means that our tox invocations do not work on platforms where ostree is not available.
- Ostree is the only plugin with additional python dependencies and the only reason which https://docs.buildstream.build/CONTRIBUTING.html#installing-build-dependencies exists, which doesn't work on Mac/Windows for example.
- There's no way to disable linting for things which
import ostreewhen ostree is not present.
Not having the ostree plugin bundled with BuildStream by default would solve these issues and greatly impove the developer experience on none-Linux platforms.
Acceptance Criteria
The above points no longer apply