skip observer testing on macOS

CoreStoreTests/TransactionTests.swift

@@ -345,6 +345,8 @@ final class TransactionTests: BaseTestCase {
         }
     }
     
+    #if os(iOS) || os(watchOS) || os(tvOS)
+    
     @objc
     dynamic func test_ThatSynchronousTransactions_CanCommitWithoutWaitingForMerges() {
         
@@ -442,6 +444,8 @@ final class TransactionTests: BaseTestCase {
         }
     }
     
+    #endif
+    
     @objc
     dynamic func test_ThatAsynchronousTransactions_CanPerformCRUDs() {