Fix CI nupkg path

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 5.0.300
+          dotnet-version: 5.x
 
       - name: Run the Cake script
         uses: cake-build/cake-action@v1
@@ -29,7 +29,7 @@ jobs:
       - uses: actions/upload-artifact@v2
         with:
           name: Reactor.nupkg
-          path: Reactor/bin/Release/netstandard2.1/Reactor.*.nupkg
+          path: Reactor/bin/Release/Reactor.*.nupkg
 
       - uses: actions/upload-artifact@v2
         with: