[.Net] update dotnet-ci and dotnet-release to use 8.0.x version when setting up .NET. And enable format check (#3136)

* use 8.0.x versin

* enable format check

* change file header

* apply code format

* add instructions in ci to fix format error

* add comment back

dotnet/test/AutoGen.SourceGenerator.Tests/FunctionCallTemplateEncodingTests.cs

@@ -1,7 +1,9 @@
-// Using directives
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// FunctionCallTemplateEncodingTests.cs
+
 using System.Text.Json; // Needed for JsonSerializer
-using Xunit; // Needed for Fact and Assert
 using AutoGen.SourceGenerator.Template; // Needed for FunctionCallTemplate
+using Xunit; // Needed for Fact and Assert
 
 namespace AutoGen.SourceGenerator.Tests
 {
@@ -89,4 +91,4 @@ namespace AutoGen.SourceGenerator.Tests
             Assert.Contains("Description = @\"This is a \"\"parameter\"\" description\"", result);
         }
     }
-}
+}