Attempt to deflake TestSSHAccessRequest (#18310)
Attempt to deflake TestSSHAccessRequest (#18310)

Migrates `approveAllAccessRequests` from polling the auth server
for access requests to leveraging a watcher. This should lead
to a significant reduction in usage of the backend in tests and
prevent `"sql: transaction has already been committed or rolled back"`
that were occurring.

gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport