bugfix in migration of collection subscriptions

[saschaszott]

In DSpace 7.5 a bug in the migration of collection subscriptions was fixed (dspace_object_id and type columns in table subscription were not filled properly) 👉 DSpace@b4f7ebf

This change was added to the CRIS code base, but later on it was (accidentally?) removed in DSpace CRIS in H2 and Postgres migration scripts.

This PR adds the missing changes to the Flyway migration scripts. Furthermore, it removes outdated subscription migration scripts which affect DSpace 7.0

[github-actions]

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[saschaszott]

Has the problem been fixed in the meantime?