Fix xevent test failures, avoid orphaned sessions (#3775)

- Added IsNotManagedInstance() for XEvents tests.

Author: paulmedynski

src/Microsoft.Data.SqlClient/tests/ManualTests/DataCommon/DataTestUtility.cs

@@ -470,6 +470,8 @@ public static bool IsEnclaveAzureDatabaseSetup()
 
         public static bool IsNotAzureSynapse() => !IsAzureSynapse;
 
+        public static bool IsNotManagedInstance() => !IsManagedInstance;
+        
         // Synapse: UDT Test Database not compatible with Azure Synapse.
         public static bool IsUdtTestDatabasePresent() => IsDatabasePresent(UdtTestDbName) && IsNotAzureSynapse();
 
@@ -1291,7 +1293,7 @@ protected virtual void OnMatchingEventWritten(EventWrittenEventArgs eventData)
 
         #nullable enable
 
-        public readonly ref struct XEventScope : IDisposable
+        public readonly ref struct XEventScope // IDisposable
         {
             #region Private Fields