apacheGH-34953: [Ruby] Change null selection behavior in `Table.slice…

…` to `:drop` (apache#34954)

### Rationale for this change

`Table.slice` behaves as `FilterOptions.null_selection_behavior = :emit_null` for backward compatibility.
But this is a differnt behavior from `Table#filter` and `Slicer::ColumnCondition#select` 
which use default option `:drop`.

This request will change the behavior of `Table#slice` to align with the default of `FilterOptions`.

### What changes are included in this PR?

Set `FilterOptions.null_selection_behavior` to the default value `:drop` from `:emit_null` .

### Are these changes tested?

Yes. Rebased after apache#34952.

### Are there any user-facing changes?

Yes.

**This PR includes breaking changes to public APIs.**

* Closes: apache#34953

Authored-by: Hirokazu SUZUKI <heronshoes877@gmail.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>

ruby/red-arrow/lib/arrow/table.rb

@@ -316,8 +316,6 @@ def slice(*args)
         end
       end
 
-      filter_options = Arrow::FilterOptions.new
-      filter_options.null_selection_behavior = :emit_null
       sliced_tables = []
       slicers.each do |slicer|
         slicer = slicer.evaluate if slicer.respond_to?(:evaluate)
@@ -339,7 +337,7 @@ def slice(*args)
           to += n_rows if to < 0
           sliced_tables << slice_by_range(from, to)
         when ::Array, BooleanArray, ChunkedArray
-          sliced_tables << filter(slicer, filter_options)
+          sliced_tables << filter(slicer)
         else
           message = "slicer must be Integer, Range, (from, to), " +
             "Arrow::ChunkedArray of Arrow::BooleanArray, " +