Is this necessary? In the old code, this is only configured once, not reconfigured before every test. I think this can be simplified to just this:

test.before(() => {
    shell.config.silent = true;
});

Or even more simply to this:

shell.config.silent = true;

Doing it each time should be harmless. But since it slows things down, it should be fine to move it out to just once before.