Re-enable `yarn unit-cli` in CI on windows

[connorjclark]

Disabled until I can get to a windows machine.

[connorjclark]

shell: process.platform === 'win32' in run-mocha-tests.js is needed.

But it seems testdouble isn't mocking modules on windows... making bin-test.js fail to run correctly. testdouble/testdouble.js#491

[connorjclark]

There is also this: https://github.com/GoogleChrome/lighthouse/runs/7290111386?check_suite_focus=true#step:6:26

introduced in #14182

will land now and fix on windows later.