dashboard: increase GO_TEST_TIMEOUT_SCALE for ppc64 builders

This sets the GO_TEST_TIMEOUT_SCALE=2 for ppc64 builders. The
runtime tests have been timing out intermittently on ppc64le
power8; it has happened on ppc64 and ppc64le power9 but
very rarely.

Updates golang/go#44422

Change-Id: I663f3f211a368a59e38fbff9ce43c925c6c7a209
Reviewed-on: https://go-review.googlesource.com/c/build/+/300870
Reviewed-by: Dmitri Shuralyov <[email protected]>
Trust: Lynn Boger <[email protected]>

Author: laboger

dashboard/builders.go

@@ -2354,18 +2354,21 @@ func init() {
 		HostType:       "host-linux-ppc64-osu",
 		FlakyNet:       true,
 		distTestAdjust: ppc64DistTestPolicy,
+		env:            []string{"GO_TEST_TIMEOUT_SCALE=2"}, // see golang.org/issues/44422
 	})
 	addBuilder(BuildConfig{
 		Name:           "linux-ppc64le-buildlet",
 		HostType:       "host-linux-ppc64le-osu",
 		FlakyNet:       true,
 		distTestAdjust: ppc64DistTestPolicy,
+		env:            []string{"GO_TEST_TIMEOUT_SCALE=2"}, // see golang.org/issues/44422
 	})
 	addBuilder(BuildConfig{
 		Name:           "linux-ppc64le-power9osu",
 		HostType:       "host-linux-ppc64le-power9-osu",
 		FlakyNet:       true,
 		distTestAdjust: ppc64DistTestPolicy,
+		env:            []string{"GO_TEST_TIMEOUT_SCALE=2"}, // see golang.org/issues/44422
 	})
 	addBuilder(BuildConfig{
 		Name:     "linux-arm64-packet",