[monotouch-tests] Fix HK tests on sonoma. (#19446)

Before this commit we had the following failing test:

```
Error: Exception Message
Expected: String matching "Objective-C exception thrown. Name: _HKObjectValidationFailureException Reason: Type HKSample can not have endDate of NSDate.distantFuture"
But was: "Objective-C exception thrown. Name: _HKObjectValidationFailureException Reason: startDate (0001-01-01 00:00:00 +0000) and endDate (4001-01-01 00:00:00 +0000) exceed the maximum allowed duration for this sample type. Maximum duration for type
```

The new exception does not happen on macOS but does on iOS.

tests/monotouch-test/HealthKit/CdaDocumentSampleTest.cs

@@ -57,11 +57,16 @@ namespace MonoTouchFixtures.HealthKit {
 #else
 					var ex = Assert.Throws<MonoTouchException> (action, "Exception");
 #endif
+
+#if MONOMAC
+					Assert.That (ex.Message, Does.Match ("startDate.*and endDate.*exceed the maximum allowed duration for this sample type"), "Exception Message");
+#else
 					if (TestRuntime.CheckXcodeVersion (15, 0)) {
 						Assert.That (ex.Message, Does.Match ("Objective-C exception thrown.  Name: _HKObjectValidationFailureException Reason: Type HKSample can not have endDate of NSDate.distantFuture"), "Exception Message");
 					} else {
 						Assert.That (ex.Message, Does.Match ("startDate.*and endDate.*exceed the maximum allowed duration for this sample type"), "Exception Message");
 					}
+#endif
 				} else {
 					action ();
 				}