Remove deprecated Parquet metadata / statistics APIs that are past the API health policy

[alamb]

Is your feature request related to a problem or challenge?

The API health policy deprecation guidelines say deprecated APIs remain for

6 major versions or 6 months, whichever is longer

main is at 55.0.0, so the next release is 56.0.0 and anything deprecated in 50.0.0 or earlier can now be removed.

Four such items remain in the datafusion-datasource-parquet crate:

Item	Deprecated in	Replacement
fetch_parquet_metadata	50.0.0	DFParquetMetadata::fetch_metadata
fetch_statistics	50.0.0	DFParquetMetadata::fetch_statistics
statistics_from_parquet_meta_calc	50.0.0	DFParquetMetadata::statistics_from_parquet_metadata
ParquetSource::predicate	50.2.0	ParquetSource::filter

Describe the solution you'd like

Remove all four items and supporting code

• While this is a breaking Rust API change, the PR should carry the api change label
• DO NOT add a note to the 56.0.0 upgrade guide, as removing deprecated APIs is clear and the compiler has guided people off them in the past

Describe alternatives you've considered

N/A

Additional context

Follow on to #23080, which did the same sweep at the 49.0.0 cutoff, and #24535.

[IljaSafronovs]

I'd like to work on this, please assign it to me

[IljaSafronovs]

take