[Devicelab] Mac ios_universal_link_test fails in CI with "No Xcode build settings have been found" #192320

Description

The Mac ios_universal_link_test devicelab task introduced in #191443 fails in post-submit CI during flutter build ios --simulator with:

This bot does not support codesigning
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[ios_universal_link_test] [STDOUT] Running Xcode build...
[ios_universal_link_test] [STDOUT] Xcode build done. 5.7s
[ios_universal_link_test] [STDOUT] Failed to build iOS app
[ios_universal_link_test] [STDOUT] Error (Xcode): No Xcode build settings have been found. Please check possible errors above.

Root Cause

1. Provisioning profile specifier in project.pbxproj: The Xcode project retained "PROVISIONING_PROFILE_SPECIFIER[sdk=iphoneos*]" = "Experimental App 0 Dev";. Headless CI machines do not have this profile installed, causing xcodebuild -showBuildSettings to fail.
2. Missing --config-only: ios_universal_link_test.dart invoked flutter build ios --simulator without --config-only. On bots without code signing support (This bot does not support codesigning), this triggered an unnecessary full build before runXcodeTests.
3. Missing deviceOperatingSystem: deviceOperatingSystem was not set to DeviceOperatingSystem.ios, causing Devicelab to default to Android device handling.
4. Scheme configuration: Runner.xcscheme had RunnerTests configured in <TestAction> instead of RunnerUITests, and RunnerUITests was missing its target dependency on Runner.