Use tar as output for docker to avoid unsupported file paths

.github/workflows/docker.yml

@@ -18,14 +18,14 @@ jobs:
           docker buildx build
           --file DiscordChatExporter.Cli.dockerfile
           --platform linux/amd64,linux/arm64
-          --output docker/
+          --output type=tar,dest=DiscordChatExporter.Cli.Docker.tar
           .
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v3
         with:
           name: DiscordChatExporter.Cli.Docker
-          path: docker/
+          path: DiscordChatExporter.Cli.Docker.tar
 
   deploy-latest:
     if: ${{ github.event_name == 'push' && github.ref_type == 'branch' && github.ref_name == 'master' }}