CI: Remove deprecated exp. from ALL_EXPERIMENTS

[dcyriller]

Disable MODULE_UNIFICATION experiment for EMBER_CLI_ALL_EXPERIMENTS CI job.

With #8827 I've set some acceptance tests behind the following conditional:

   if (!isExperimentEnabled('MODULE_UNIFICATION')) {
    it(
      'addons with standard preprocessors compile correctly',
      co.wrap(function*() {
        ...
      })
    );
  }

That PR would disable some acceptance tests for EMBER_CLI_ALL_EXPERIMENTS test scenario. This PR aims at fixing that.