syncs: stop running TestWatchMultipleValues on CI

It's flaky, and not just on Windows.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>

syncs/watchdog_test.go

@@ -6,7 +6,6 @@ package syncs
 
 import (
 	"context"
-	"runtime"
 	"sync"
 	"testing"
 	"time"
@@ -49,11 +48,11 @@ func TestWatchContended(t *testing.T) {
 }
 
 func TestWatchMultipleValues(t *testing.T) {
-	if cibuild.On() && runtime.GOOS == "windows" {
+	if cibuild.On() {
 		// On the CI machine, it sometimes takes 500ms to start a new goroutine.
 		// When this happens, we don't get enough events quickly enough.
 		// Nothing's wrong, and it's not worth working around. Just skip the test.
-		t.Skip("flaky on Windows CI")
+		t.Skip("flaky on CI")
 	}
 	mu := new(sync.Mutex)
 	ctx, cancel := context.WithCancel(context.Background())