Move iOS Swift unit tests back to Cirrus (flutter#3221)

They are hanging frequently on LUCI now, even though they used to (at least mostly) work.

Updates the simulator to use one available on the current LUCI machines, and adds a step to Cirrus to ensure the creation of a matching simulator so that the script works on both. (Currently it appears that Cirrus by default only has iPhone 14, which LUCI doesn't have by default.)

.cirrus.yml

@@ -340,6 +340,11 @@ task:
         matrix:
           CHANNEL: "master"
           CHANNEL: "stable"
+      # Create an iPhone 13, to match what is available on LUCI, since Pigeon tests
+      # currently have a hard-coded device.
+      create_simulator_script:
+        - xcrun simctl list
+        - xcrun simctl create "iPhone 13" com.apple.CoreSimulator.SimDeviceType.iPhone-13 com.apple.CoreSimulator.SimRuntime.iOS-16-0
       local_tests_script:
         # script/configs/linux_only_custom_test.yaml
         #   Custom tests need Chrome for these packages. (They run in linux-custom_package_tests)

packages/pigeon/tool/run_tests.dart

@@ -49,7 +49,6 @@ Future<void> main(List<String> args) async {
   // separation. See https://github.com/flutter/flutter/issues/120231.
   const List<String> macOSHostLuciTests = <String>[
     iOSObjCUnitTests,
-    iOSSwiftUnitTests,
     // TODO(stuartmorgan): Enable by default once CI issues are solved; see
     // https://github.com/flutter/packages/pull/2816.
     //iOSObjCIntegrationTests,
@@ -60,6 +59,7 @@ Future<void> main(List<String> args) async {
     // iOSSwiftIntegrationTests,
   ];
   const List<String> macOSHostCirrusTests = <String>[
+    iOSSwiftUnitTests,
     macOSSwiftUnitTests,
     macOSSwiftIntegrationTests,
   ];

packages/pigeon/tool/shared/test_suites.dart

@@ -303,7 +303,7 @@ Future<int> _runIOSPluginUnitTests(String testPluginPath) async {
   return runXcodeBuild(
     '$examplePath/ios',
     sdk: 'iphonesimulator',
-    destination: 'platform=iOS Simulator,name=iPhone 8',
+    destination: 'platform=iOS Simulator,name=iPhone 13',
     extraArguments: <String>['test'],
   );
 }