try fix github actions

Author: isc30

.github/workflows/dotnet-core-ubuntu.yml

@@ -2,6 +2,11 @@ name: .NET Core (Ubuntu)
 
 on: [push]
 
+env:
+    # Workaround for GitVersionTask bug in combination with .NET Core SDK 3.1.200
+    # (see, e.g., https://github.com/dotnet/sdk/issues/10878 and https://github.com/GitTools/GitVersion/issues/2063)
+    MSBUILDSINGLELOADCONTEXT: 1
+
 jobs:
   build:
 
@@ -26,5 +31,5 @@ jobs:
     - name: Pack with dotnet
       run: dotnet pack -c Release .\\BlazorLazyLoading.sln
 
-    - name: Push package to NuGet
-      run: dotnet nuget push **/*.nupkg --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json
+    #- name: Push package to NuGet
+    #  run: dotnet nuget push **/*.nupkg --api-key ${{ secrets.NUGET_API_KEY }} --source https://api.nuget.org/v3/index.json