ci: pre-boot iOS simulator before xharness in CI

xharness/mlaunch's internal boot sequence (shutdown, disable watchdogs,
reboot) is flaky on CI, causing simctl launch to hang. Pre-booting the
simulator with simctl boot/bootstatus avoids this by ensuring it's fully
ready before xharness runs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jpnurmi

scripts/device-test.ps1

@@ -64,6 +64,11 @@ try
 
         $udid = Get-IosSimulatorUdid -Verbose
         if ($udid) {
+            if ($CI) {
+                Write-Host "Pre-booting simulator $udid..."
+                xcrun simctl boot $udid 2>&1 | Write-Host
+                xcrun simctl bootstatus $udid 2>&1 | Write-Host
+            }
             $arguments += @('--device', $udid)
         } else {
             Write-Host "No suitable simulator found; proceeding without a specific --device"