Prior to this change, when there was an existing add-on purchase record
(`GitlabSubscriptions::AddOnPurchase`) for the SM instance (`namespace`
is `nil`) and that record is expired, the license data sync would fail.
This was because the record can't be found because the lookup for the
add-on purchase was looking for a not expired record by using the
`active` scope. As a result a new add-on purchase record was attempted
to be created which would then fail due to the uniqueness validation of
the `subscription_add_on_id` scoped to `namespace_id`.

In this change, the `active` record is removed to allow finding the
add-on purchase record and updating it regardless of being active or
expired.

Changelog: fixed
EE: true