Update to Arcade 10

[ViktorHofer]

Arcade 10 is the new "LTS" experience for infrastructure. The repo currently still uses Arcade 8 which doesn't get many fixes anymore.

[ericstj]

Should the subscription be from arcade or dotnet?
Which channel should we use? We used to have channels like .NET 8 Eng I see there is .NET 10 Eng.

I went ahead and created https://maestro.dot.net/subscriptions?search=508c4a9d-7a92-4c93-b6bd-f74fab408368&showDisabled=False based on pre-VMR assumptions. It created #249

@mmitche can you review questions and what I've done and let me know what you think?

[ViktorHofer]

Repos outside of the VMR should continue to subscribe to Arcade directly, so NET 10 Eng is right.

[mmitche]

Technically it's fine to subscribe to either for a repo outside of the VMR. However, for an arcade fix to 10, the path from arcade fix->vmr->repo is longer than arcade->repo, so it's generally more preferable to take .NET 10 Eng, if you're not having to align with source backflow.