deposit.loader: Remove no longer used deprecated loader
deposit.signals: Remove compatibility code
The deposit service only sends message for the current new deposit loader.
Test Plan
tox
Migrated from D2402 (view on Phabricator)
Staging instance, all changes can be removed at any time
deposit.signals: Remove compatibility code
The deposit service only sends message for the current new deposit loader.
tox
Migrated from D2402 (view on Phabricator)