Add purplesyringa to cloud-compute

[purplesyringa]

I wanted to work on some LLVM features to improve unwinding support on Windows but don't really have enough compute to play around with LLVM. @ChrisDenton told me I could ask for a dev desktop here.

[github-actions]

Dry-run check results

[WARN  sync_team] sync-team is running in dry mode, no changes will be applied.
[INFO  sync_team] synchronizing github
[INFO  sync_team] 💻 Team Diffs:
    📝 Editing team 'rust-lang/cloud-compute-team':
      Adding member 'purplesyringa' with member role

[ChrisDenton]

I'd love for purplesyringa to have access to the dev desktops to help investigate and improve our unwinding support!

[marcoieni]

FYI: we don't have windows in cloud compute. it's just ubuntu machines.
Not sure if windows is required for you work.

[purplesyringa]

I was going to compile LLVM on Linux for the Windows target, so that I could develop rustc on Linux and test the resulting binaries on Windows. But thanks :)

[jackh726]

This list is growing and we might want to do some kind of administrative task at some point to better manage this, but for now I'm following the status quo. There's no real owner for this marker team, so I'm taking @ChrisDenton's vouch as an approval here.