cmd: remove js runtime workaround

The js/wasm bug meant that printing to stdout in the e2e app would crash
the runtime, so we couldn't synchronize with the app like in the other
drivers.

Now that the bug is fixed, we can do the same as the other drivers just
fine.

Signed-off-by: Daniel Martí <mvdan@mvdan.cc>

cmd/gogio/testdata/red.go

@@ -8,7 +8,6 @@ import (
 	"image"
 	"image/color"
 	"log"
-	"runtime"
 
 	"gioui.org/app"
 	"gioui.org/f32"
@@ -82,13 +81,6 @@ func loop(w *app.Window) error {
 
 			e.Frame(gtx.Ops)
 
-			if runtime.GOOS == "js" {
-				// TODO(mvdan): Unfortunately, printing to
-				// stdout crashes the js/wasm port. Use the
-				// prints once the issue is fixed:
-				// https://github.com/golang/go/issues/35256
-				break
-			}
 			switch notify {
 			case notifyInvalidate:
 				notify = notifyPrint