Update .net sdk version in CI

Author: SKProCH

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8
       - uses: actions/cache@v1
         with:
           path: ~/.nuget/packages