Update dotnet.yml

Author: enisgurkann

.github/workflows/dotnet.yml

@@ -9,15 +9,10 @@ jobs:
       matrix:
         os: [ubuntu-latest]
     steps:
-    - name: Setup .NET 5.0
+    - name: Setup .NET Core 6.0
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.101
-  
-    - name: Setup .NET Core 3.1
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 3.1.403
+        dotnet-version: 6.0.x
       if: matrix.os == 'ubuntu-latest'
     - uses: actions/checkout@v1
     - name: Build