sweet: require heap profiles to be available in cockroach benchmark

Currently the cockroachdb benchmark is failing in TestSweetEndToEnd
because CPU profiling fails (and thus PGO-based builds fail). Fix this
by requiring that some profile be obtainable for each instance before
starting the benchmark properly. I suspect there is an internal race,
wherein even if the server is up and running by some metric, CPU
profiles aren't yet ready.

For #56958.

Change-Id: I4c907b4394f249f3f1cac6768e641fafda20f511
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/614536
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
1 file changed