Breaking change in Avro 1.12.1 affects parquet-avro users: logical types now deserialize to different Java types

## Summary

Avro 1.12.1 introduces a breaking change that affects `parquet-avro` users. Multiple logical types are now deserialized to their proper Java types instead of their underlying primitive types when using `ReflectData`, causing `ClassCastException` in existing code.

## Background

- **Upstream issue:** https://issues.apache.org/jira/browse/AVRO-3989
- **Pull request:** https://github.com/apache/avro/pull/3354
- **Avro version affected:** 1.12.1 (released as a patch version)

## Problem

The fix in AVRO-3989 changed the deserialization behavior for ALL logical types. When using within parquet-avro `ReflectData` or `SpecificData` classes, these fields now return their logical Java type objects instead of their underlying primitive types from `GenericRecord`.

### Affected logical types and conversions:

| Logical Type | Old Type (≤1.12.0) | New Type (1.12.1) |
|--------------|-------------------|-------------------|
| `timestamp-millis` | `Long` | `Instant` |
| `timestamp-micros` | `Long` | `Instant` |
| `date` | `Integer` | `LocalDate` |
| `time-millis` | `Integer` | `LocalTime` |
| `time-micros` | `Long` | `LocalTime` |
| `local-timestamp-millis` | `Long` | `LocalDateTime` |
| `local-timestamp-micros` | `Long` | `LocalDateTime` |
| `uuid` | `String` | `UUID` |
| `decimal` | `ByteBuffer` | `BigDecimal` |

This breaks existing code that expects primitive values:

```java
// This used to work in Avro 1.12.0
Long timestamp = (Long) genericRecord.get("timestamp_field");
Integer date = (Integer) genericRecord.get("date_field");
String uuid = (String) genericRecord.get("uuid_field");

// In Avro 1.12.1, all of these throw ClassCastException
// because values are now Instant, LocalDate, UUID, etc.
```

## Impact

- **Widespread breakage:** Affects anyone using parquet-avro with ANY logical types
- Code that has worked for years suddenly breaks after a patch version update
- The breaking nature wasn't clearly documented in Avro's changelog
- This is a significant behavior change that affects the entire logical type system

## Heads up for future avro updates

I apologize if this isn't the right place to report this, please feel free to redirect me if there's a better venue for this discussion. My main goal is to ensure that when parquet-java does consider updating Avro, the team and users are aware of this significant behavioral change.

## For Current Users

If you're using parquet-avro and explicitly upgrading Avro to 1.12.1+ in your project, be aware of this breaking change. You'll need to update code that reads logical type fields from `GenericRecord`.

Commencez par le lien AVRO-3989 de l’issue et le comportement de ReflectData, SpecificData et GenericRecord décrit ici ; aucun fichier ni test parquet-java n’est nommé. Comparez la gestion des types logiques listés dans Avro 1.12.0 et 1.12.1, puis déterminez avec les maintainers quelle modification ou documentation est attendue avant de définir ce qui constitue l’achèvement.

Rédigé par le modèle d'indexation à partir du texte de l'issue.