`ThriftMetadataWriter::write_column_indexes` cannot handle a `ColumnIndexMetaData::NONE`

[etseidl]

Describe the bug
While testing #8811 I found that trying to concatenate alltypes_tiny_pages.parquet from the parquet-testing repo fails with the error "Cannot serialize NONE index". While creating a Parquet file from scratch, the column index may contain None entries. But when reading from a file with missing indexes, a ColumnIndexMetaData::NONE will be inserted because the current metadata requires a value. When trying to serialize this, the ColumnIndexMetaData::NONE is encountered and triggers the error.

To Reproduce
Use parquet-concat from #8811 on parquet-testing/data/alltypes_tiny_pages.parquet.

Expected behavior
A ColumnIndexMetaData::NONE should simply be skipped.

Additional context

[etseidl]

This error once again makes me want to change the page indexes to Vec<Vec<Option<X_IndexMetaData>>>.

[alamb]

label_issue.py automatically added labels {'parquet'} from #8817