* deps: upgrade parquet-go to v0.32.0
Iceberg compaction writes the merged file with the schema of its first
input, encodings included. parquet-go before v0.31.0 took the deprecated
PLAIN_DICTIONARY encoding that DuckDB writes at face value and encoded
those pages as plain int32 indices, but the spec gives PLAIN_DICTIONARY
the same bit-width-prefixed RLE layout as RLE_DICTIONARY. Every
dictionary-encoded column in a compacted file then decoded onto a single
dictionary entry, and anything past one page failed to decode at all.
* iceberg: cover compaction of dictionary-encoded input
The fixture is a DuckDB-written file, so it carries the PLAIN_DICTIONARY
encoding a Go writer will not produce.
* iceberg: tally whole rows in the dictionary merge test
Counting each column on its own passes a merge that remaps names while
leaving their cardinality intact.
