[BUG] Parquet writer unable to set nullability to false on columns with no nulls

[vuule]

Parquet writer seems too stringent with its checks to write columns as not nullable.
The following cases fail to write when set_nullability(false) is called on the input metadata:

• Column with no nulls;
• Sliced column that only has nulls outside of the slice.

This behaviors limits the use of the nullable option.

Repro code:

  column_wrapper<int32_t> ages_col{{1, 2, 3}};
  auto valids = cudf::detail::make_counting_transform_iterator(0, [](auto i) { return i > 1; });
  cudf::test::structs_column_wrapper col5{{ages_col}, valids};

  table_view expected({col5});

  cudf::io::table_input_metadata expected_metadata(expected);
  expected_metadata.column_metadata[0].set_nullability(false);

  auto expected_slice = cudf::slice(expected, {1, 3});

  auto filepath = temp_env->get_temp_filepath("SlicedTable.parquet");
  cudf::io::parquet_writer_options out_opts =
    cudf::io::parquet_writer_options::builder(cudf::io::sink_info{filepath}, expected_slice)
      .metadata(&expected_metadata);
  cudf::io::write_parquet(out_opts);

To test the case where the column has no nulls, modify valids to always return true.

[vuule]

Issue partially blocks a Python feature #12952 (part of the PR got reverted in #12996)

[GregoryKimball]

I believe this is closed by #13675

[vuule]

@GregoryKimball #13675 does not address the sliced column case