chore: updated workflow to .NET 8

.github/workflows/dotnet.yml

@@ -9,14 +9,14 @@ on:
 jobs:
   build:
 
-    runs-on: windows-latest
+    runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
     - name: Setup .NET
       uses: actions/setup-dotnet@v2
       with:
-        dotnet-version: 6.x.x
+        dotnet-version: 8.x.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build