- use correct .net version

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
       uses: actions/checkout@v1
     - uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: '8.0.x'
     - name: Build
       run: dotnet build
   
@@ -26,7 +26,7 @@ jobs:
       uses: actions/checkout@v1
     - uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: '8.0.x'
     - name: Run tests
       run: dotnet test