Try use Net Core 3.1 SDK for netcoreapp2.0

Author: alex-kulakov

.github/actions/setup-dotnets/action.yml

@@ -51,4 +51,4 @@ runs:
       if: ${{ contains(inputs.target_framework, '2.0') }}
       uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '5.0.x'
+        dotnet-version: '3.1.402'