dashboard: unset known issue for NetBSD 9.0 builders, use for trybots

The NetBSD 9.0 builders are operational as of CL 227538. They've been
running on a few commits in all repositories without issues.

The netbsd/386 builder is passing, no longer hanging in the runtime
tests as the NetBSD 8.0 version did, so keep it enabled.

If anything unexpected comes up, we should investigate.

For golang/go#37244.
For golang/go#31726.

Change-Id: Ie3167fa3eabb7f707487561ca2cd4505572df741
Reviewed-on: https://go-review.googlesource.com/c/build/+/227545
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
diff --git a/dashboard/builders_test.go b/dashboard/builders_test.go
index 9ec53ee..051e31b 100644
--- a/dashboard/builders_test.go
+++ b/dashboard/builders_test.go
@@ -180,7 +180,7 @@
 				"linux-386",
 				"linux-amd64",
 				"linux-amd64-race",
-				"netbsd-amd64-8_0",
+				"netbsd-amd64-9_0",
 				"openbsd-386-64",
 				"openbsd-amd64-64",
 				"windows-386-2008",
@@ -386,6 +386,10 @@
 		{b("netbsd-amd64-8_0", "net"), onlyPost},
 		{b("netbsd-386-8_0", "go"), none},
 		{b("netbsd-386-8_0", "net"), none},
+		{b("netbsd-amd64-9_0", "go"), onlyPost},
+		{b("netbsd-amd64-9_0", "net"), onlyPost},
+		{b("netbsd-386-9_0", "go"), onlyPost},
+		{b("netbsd-386-9_0", "net"), onlyPost},
 
 		// AIX starts at Go 1.12
 		{b("aix-ppc64", "go"), onlyPost},