Fixed build

Author: FabianGosebrink

.github/workflows/dotnetcore.yml

@@ -8,9 +8,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v3
     - name: Setup .NET Core
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v2
       with:
         dotnet-version: '6.0.x'
     - name: Build with dotnet