Now we have `table-joiner`, we can tweak how `endoflifedate`
functionality works to reduce unnecessary duplication in the table
generation, similar to `osvdev`, by creating a multi-join-able table.

This requires a refactor of the existing table schema for
end-of-life data, which is a breaking change.

We can also simplify the query by looking at distinct packages across
the projects, instead of retrieving everything, which in a larger
database, resulted in 1/5 the size of queried rows.

To make the `JOIN` work, we need a slightly more complex `inner join`,
which makes sure to handle the (newly added) `current_version` field, as
it may be NULL.