[FE+version control] Surface feature in Stable and update DevHome.Helpers to 1.0.20240910-x0103

[DefaultRyan]

Detailed description of the pull request / Additional comments

This removes some older workaround code that was used for internal validation in the helpers package. There are some older internal Windows builds we'll start excluding by reporting the feature as not present. But I think we're fine at this point. This will also allow us to be more selective about which public, external Windows builds we'll report the feature present on.

Between this cleanup, using the featurePresenceCheck, and the increasingly stable state of the FE+git integration, I believe we're ready to make this feature visible but disabled by default in the stable build. This will make it even easier for internal selfhosters to try out the feature and for Windows Beta seekers to try it out as we start rolling out the Windows infrastructure publicly.

Validation steps performed

Ran the registration/unregistration flows with the new package and validated that everything still works as expected, just to rule out any silly mistakes.

[krschau]

I believe we discussed that surfacing in stable would allow us to mark #679 as done. Are we still good to do that?

[DefaultRyan]

I believe we discussed that surfacing in stable would allow us to mark #679 as done. Are we still good to do that?

I'm probably fine with it, but maybe consider waiting until we're ready to set it to enabled by default? I know there's some finishing touches we're still working on, and even though it's enable-able in Stable, it's still off by default and won't even be visible unless the OS features are active.

What's Dev Home's typical bar to meet for this sort of thing?

[krschau]

What's Dev Home's typical bar to meet for this sort of thing?

We've been deciding on a case-by-case basis. Happy to wait for until it's enabled by default, I'll move it out a couple milestones and put a note in the issue that it is available to be turned on.