Remove legacy check for outdated solution file format in ITestTaskSettings.

Author: darthsharp

source/CakeBuild/CreativeCoders.CakeBuild/Tasks/Templates/Settings/ITestTaskSettings.cs

@@ -10,11 +10,11 @@ IEnumerable<FilePath> TestProjects
     {
         get
         {
-            if (Context.SolutionFile.GetExtension()?.ToLower() != ".sln")
-            {
-                // Currently no support for new XML based slnx solution file format
-                return [];
-            }
+            // if (Context.SolutionFile.GetExtension()?.ToLower() != ".sln")
+            // {
+            //     // Currently no support for new XML based slnx solution file format
+            //     return [];
+            // }
 
             var solution = Context.ParseSolution(Context.SolutionFile);