dashboard: adjust the windows-amd64-longtest policy

It shouldn't build more repos than windows-amd64-2016.

Fixes golang/go#35185

Change-Id: I310e2ccc521d88692fcf904fe53b4bae94f3f0f0
Reviewed-on: https://go-review.googlesource.com/c/build/+/203885
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/dashboard/builders_test.go b/dashboard/builders_test.go
index 51f4f5f..0fe9072 100644
--- a/dashboard/builders_test.go
+++ b/dashboard/builders_test.go
@@ -458,6 +458,11 @@
 		{b("linux-amd64-longtest", "net"), onlyPost},
 		{b("linux-amd64-longtest@go1.12", "go"), onlyPost},
 		{b("linux-amd64-longtest@go1.12", "net"), none},
+		{b("windows-amd64-longtest", "go"), onlyPost},
+		{b("windows-amd64-longtest@go1.13", "go"), onlyPost},
+		{b("windows-amd64-longtest", "net"), onlyPost},
+		{b("windows-amd64-longtest", "exp"), onlyPost},
+		{b("windows-amd64-longtest", "mobile"), none},
 
 		// Experimental exp repo runs in very few places.
 		{b("linux-amd64", "exp"), both},