[terraform] Deploy Tunnelbroker 0.8 to staging

Summary: Tunnelbroker hasn't been published since January, and there were some refactors meanwhile that cause compatibility issues with QR auth

Test Plan: terraform plan. If this one goes well on staging, I'll deploy to prod as well

Reviewers: ashoat, kamil, will

Reviewed By: ashoat, kamil

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D12103