Use the CTS --quiet flag.

This PR adds the --quite flag into the CTS runner command line. This
will suppress the summary information and the duplicate failure
information as it's already output by the run-cts test runner.

Change-Id: I4e885d416c7ab679551e76f3fc702aa7b5a3535f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/87900
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

src/dawn/node/tools/src/cmd/run-cts/main.go

@@ -947,6 +947,7 @@ func (r *runner) runTestcase(query string) result {
 		// Actual arguments begin here
 		"--gpu-provider", r.dawnNode,
 		"--verbose",
+		"--quiet",
 	}
 	for _, f := range r.flags {
 		args = append(args, "--gpu-provider-flag", f)