Question: can you also exclude files in the glob

I am trying to all files that have the msixupload file extension; except the ones that contain Tests in the file name. what would be the best filter.

I now had, but seems it doesn't support exclusions or am I doing something wrong?
````
        files: |
          ./**/Packages/**/*.msixupload
          !./**/*Tests*.msixupload
````