fix: sort a ranked union in ETS, not only a ranked union_all

[matt-beanland]

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• Update dependencies

Summary

Fixes #2827 .

Sorting by a combination calculation did nothing when the parts were joined with union. The
same query with union_all sorted correctly. One record, reached by three parts ranking it
1/2/3, sorted descending:

union_all -> [3, 2, 1]     correct
union     -> [1, 2, 3]     unsorted

That is the ranked shape the combinations guide documents. Repro in the issue.

Cause

run_query/3 in lib/ash/data_layer/ets/ets.ex tells Ash.Actions.Sort.runtime_sort/3 whether
the fold can return the same primary key twice:

maybe_not_distinct? = Enum.any?(combination_of, &(elem(&1, 0) == :union_all))

runtime_sort/3 uses maybe_not_distinct? when choosing how to load the sort key — batched, or one record at a time. The batched branch cannot resolve two records sharing a primary key into two records, so the key
is mis-assigned and the sort silently does nothing.

The condition is too narrow. union_all is not the only way to get a repeated primary key: for a
union the equality basis is the combination fieldset, so parts carrying different combination
calculations keep both copies.

Now widening to any part carrying combination calculations:

maybe_not_distinct? =
  Enum.any?(combination_of, fn {type, combination} ->
    type == :union_all or not Enum.empty?(combination.calculations)
  end)

Ash.Query.Combination's calculations defaults to %{}, so the emptiness test has to be
Enum.empty?/1. Comparing against [] is true for %{}, which would set the flag for every
combination query and put them all on the unbatched path.

Commits

1. test: pin the ranked three-part shape from the guide, asserted for union_all - passes as-is.
2. fix: widen the condition, and assert the same result for union.

[zachdaniel]

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