Reduce number of boskos clusters (#2187)
Reduce number of boskos clusters (#2187)

https://velodrome.istio.io/dashboard/db/boskos-dashboard?orgId=1&from=now-30d&to=now

We have not used more than 10 in the last 30 days
istio/test-infra,istio/test-infra,istio/test-infra,istio/test-infra