remove package org.dspace.subscriptions.dSpaceObjectsUpdates

[saschaszott]

Description

The classes in the Java package org.dspace.subscriptions.dSpaceObjectsUpdates are no longer used. They were (partially) replaced by the classes in the Java package org.dspace.subscriptions.objectupdates

This PR suggests the removal of the package org.dspace.subscriptions.dSpaceObjectsUpdates from the code base.

[github-actions]

This pull request has been automatically marked as stale because it has not had
activity in one year. It will be closed in 14 days if no further activity occurs.

Allowing pull requests to close as stale helps us filter out old work that is no longer
relevant and helps developers focus on reviewing current work.

All pull requests closed by this bot act like normal pull requests;
they can be searched for, commented on or reopened at any point.

If these changes are still relevant then please comment and/or rebase your PR based on the
latest DSpace code. This will remove the stale status and notify us to assign a reviewer
for your PR.

[saschaszott]

Has the problem been fixed in the meantime?