(#192) CI: update to .NET 8 SDK

Author: ForNeVeR

.github/workflows/main.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Set up .NET SDK
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8.0.x
       - name: NuGet cache
         uses: actions/cache@v4
         with: