dashboard: revert accidental inclusion of nacl subrepo trybots

Fixes golang/go#28582

Change-Id: Ie3bbb9f4dc1a12c5c4a838165c81f5e2a762a9fe
Reviewed-on: https://go-review.googlesource.com/c/147337
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index c35d83a..3c15045 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -1286,7 +1286,7 @@
 	addBuilder(BuildConfig{
 		Name:              "nacl-386",
 		HostType:          "host-nacl-kube",
-		tryBot:            defaultTrySet(),
+		tryBot:            explicitTrySet("go"),
 		MaxAtOnce:         2,
 		numTryTestHelpers: 3,
 		env:               []string{"GOOS=nacl", "GOARCH=386", "GOHOSTOS=linux", "GOHOSTARCH=amd64"},
@@ -1294,7 +1294,7 @@
 	addBuilder(BuildConfig{
 		Name:              "nacl-amd64p32",
 		HostType:          "host-nacl-kube",
-		tryBot:            defaultTrySet(),
+		tryBot:            explicitTrySet("go"),
 		MaxAtOnce:         2,
 		numTryTestHelpers: 3,
 		env:               []string{"GOOS=nacl", "GOARCH=amd64p32", "GOHOSTOS=linux", "GOHOSTARCH=amd64"},