Remove ProjectDailyStatisticsWorker (and queue)

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That's a follow from https://gitlab.com/gitlab-com/gl-infra/scalability/-/issues/256, here we'll need to:

1. Remove the feature flag that makes it enqueue jobs to this worker
2. Consider either migrating existing jobs in the queue and process them, or just removing the queue in a major release (a few jobs can be missed in the latter)
3. Remove ProjectDailyStatisticsWorker and queue