zoekt-sourcegraph-indexserver: set internal actor on requests (#219)
Requests from zoekt-sourcegraph-indexserver do not have actor IDs set,
which means our actor middleware must treat an unset actor header as
an internal user. This change explicitly sets an internal actor on outgoing
requests, which removes the need for such a workaround.
Related: https://github.com/sourcegraph/sourcegraph/issues/28451