CI: always upload build artifact

This is needed to access the kernel built by ci runs on other branches, it still only creates a release when using the master branch.

Author: Redecorating

.github/workflows/build.yml

@@ -45,7 +45,6 @@ jobs:
           ls -l
 
       - name: Upload package artifact
-        if: github.ref == 'refs/heads/master'
         uses: actions/upload-artifact@v2
         with:
           name: linux-mbp-${{ steps.build.outputs.tag }}