dashboard: switch iOS hardware

Jakob Borg kindly supplied a new iPhone 6 to replace the ailing
iPhone 5 (arm) and iPhone 6 (arm64) that currenctly runs the iOS
builders.

The new phone runs iOS 10 that can run both arm and arm64, so
instead of replacing the device ids specified with GOIOS_DEVICE_ID,
simply remove them altogether.

Change-Id: I36cf574a902b953a3d2bf2a5de50741dff1b940d
Reviewed-on: https://go-review.googlesource.com/119415
Run-TryBot: Elias Naur <elias.naur@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

dashboard/builders.go

@@ -1340,14 +1340,14 @@ func init() {
 	addBuilder(BuildConfig{
 		Name:     "darwin-arm-a1428ios",
 		HostType: "host-darwin-amd64-eliasnaur-ios",
-		Notes:    "iPhone 5 (model A1428), via a Mac Mini; owned by elias.naur",
-		env:      []string{"GOARCH=arm", "GOIOS_DEVICE_ID=608470ed34dc459328dd4cfa35ca5757b9c65222"},
+		Notes:    "iPhone 6 (model A1586), via a Mac Mini; owned by elias.naur",
+		env:      []string{"GOARCH=arm"},
 	})
 	addBuilder(BuildConfig{
 		Name:     "darwin-arm64-a1549ios",
 		HostType: "host-darwin-amd64-eliasnaur-ios",
-		Notes:    "iPhone 6 (model A1549), via a Mac Mini; owned by elias.naur",
-		env:      []string{"GOARCH=arm64", "GOIOS_DEVICE_ID=e5d8bf44318afed071f97d479c3e5456be8b8c17"},
+		Notes:    "iPhone 6 (model A1586), via a Mac Mini; owned by elias.naur",
+		env:      []string{"GOARCH=arm64"},
 	})
 	addBuilder(BuildConfig{
 		Name:     "android-arm-wiko-fever",