dashboard: enable SkipSnapshot for openbsd-arm-jsing builder

The builder network is too slow/distant to upload snapshots successfully.

Updates golang/go#25498

Change-Id: Ida86eb1f84e34c9810227c98370cef980529796f
Reviewed-on: https://go-review.googlesource.com/c/build/+/228238
Reviewed-by: Dmitri Shuralyov <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: 4a6f656c

dashboard/builders.go

@@ -1935,6 +1935,7 @@ func init() {
 	addBuilder(BuildConfig{
 		Name:           "openbsd-arm-jsing",
 		HostType:       "host-openbsd-arm-joelsing",
+		SkipSnapshot:   true,
 		distTestAdjust: noTestDirAndNoReboot,
 		tryBot:         nil,
 		env: []string{