[fix] fixed extern mocking

Author: MchKosticyn

VSharp.CSharpUtils/ExternMocker.cs

@@ -10,11 +10,13 @@ namespace VSharp.CSharpUtils;
 
 public static class ExternMocker
 {
-    public static bool ExtMocksSupported =
+    public static readonly bool ExtMocksSupported =
         !OperatingSystem.IsMacOS()
         || RuntimeInformation.OSArchitecture == Architecture.X86
         || RuntimeInformation.OSArchitecture == Architecture.X64;
 
+    public static readonly bool ShimSupported = Environment.Version.Major <= 6;
+
     private static List<NativeDetour> _detours = new();
 
     public static IntPtr GetExternPtr(string libName, string methodName)

VSharp.SILI/Interpreter.fs

@@ -957,7 +957,7 @@ type internal ILInterpreter() as this =
         isIntrinsic && (Array.contains fullMethodName x.TrustedIntrinsics |> not)
 
     member private x.ShouldMock (method : Method) fullMethodName =
-        Loader.isShimmed fullMethodName
+        Loader.isShimmed fullMethodName && ExternMocker.ShimSupported
         || method.IsExternalMethod && not method.IsQCall
 
     member private x.InstantiateThisIfNeed state thisOption (method : Method) =