Use resolve for xunit tool path

build.cake

@@ -352,10 +352,12 @@ Task("Run-Leak-Tests")
         var report = "tests\\Avalonia.LeakTests\\bin\\Release\\report.xml";
         if(System.IO.File.Exists(report))
             System.IO.File.Delete(report);
+
+        var tool = Context.Tools.Resolve("xunit.console.x86.exe").FullPath;
         var proc = System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
         {
             FileName="tests\\Avalonia.LeakTests\\toolproject\\bin\\dotMemoryUnit.exe",
-            Arguments="-targetExecutable=\"tools\\xunit.runner.console\\tools\\xunit.console.x86.exe\" -returnTargetExitCode  -- tests\\Avalonia.LeakTests\\bin\\Release\\Avalonia.LeakTests.dll -xml tests\\Avalonia.LeakTests\\bin\\Release\\report.xml ",
+            Arguments="-targetExecutable=\"" + tool + "\" -returnTargetExitCode  -- tests\\Avalonia.LeakTests\\bin\\Release\\Avalonia.LeakTests.dll -xml tests\\Avalonia.LeakTests\\bin\\Release\\report.xml ",
             UseShellExecute = false,
         });
         var st = System.Diagnostics.Stopwatch.StartNew();