[BUG] 2.0.57版本 Could not write JSON: Attempt to get length of null array 给null或者给空的数组也不行

### 问题描述
Caused by: java.io.IOException: Could not write JSON: Attempt to get length of null array
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.support.retrofit.Retrofit2ConverterFactory$RequestBodyConverter.convert(Retrofit2ConverterFactory.java:139)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.support.retrofit.Retrofit2ConverterFactory$RequestBodyConverter.convert(Retrofit2ConverterFactory.java:113)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at retrofit2.ParameterHandler$Body.apply(ParameterHandler.java:438)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W ... 19 more
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W Caused by: java.lang.NullPointerException: Attempt to get length of null array
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterBaseModule$WriterAnnotationProcessor.getFieldInfo(ObjectWriterBaseModule.java:311)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterProvider.getFieldInfo(ObjectWriterProvider.java:235)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterCreator.creteFieldWriter(ObjectWriterCreator.java:147)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterCreator.lambda$createObjectWriter$1$com-alibaba-fastjson2-writer-ObjectWriterCreator(ObjectWriterCreator.java:377)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterCreator$$ExternalSyntheticLambda1.accept(D8$$SyntheticClass:0)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.util.BeanUtils.declaredFields(BeanUtils.java:324)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.util.BeanUtils.declaredFields(BeanUtils.java:255)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterCreator.createObjectWriter(ObjectWriterCreator.java:374)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterProvider.getObjectWriterInternal(ObjectWriterProvider.java:464)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterProvider.getObjectWriter(ObjectWriterProvider.java:340)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.JSONWriter.getObjectWriter(JSONWriter.java:555)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterObject.getObjectWriterVoid(FieldWriterObject.java:154)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterObject.getObjectWriter(FieldWriterObject.java:76)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterObject.writeInternal(FieldWriterObject.java:351)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterObject.write(FieldWriterObject.java:247)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterAdapter.write(ObjectWriterAdapter.java:312)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterList.writeList(FieldWriterList.java:378)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterListMethod.write(FieldWriterListMethod.java:79)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriter6.write(ObjectWriter6.java:80)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterList.writeList(FieldWriterList.java:378)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.FieldWriterListMethod.write(FieldWriterListMethod.java:79)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.writer.ObjectWriterAdapter.write(ObjectWriterAdapter.java:312)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.JSON.toJSONBytes(JSON.java:3517)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W at com.alibaba.fastjson2.support.retrofit.Retrofit2ConverterFactory$RequestBodyConverter.convert(Retrofit2ConverterFactory.java:130)
2025-05-09 10:51:42.682 6152-6152 System.err com.txc.mms.pad W ... 21 more

### 相关日志输出
*请复制并粘贴任何相关的日志输出。*

#### 附加信息
*如果你还有其他需要提供的信息，可以在这里填写（可以提供截图、视频等）。*

Start with com.alibaba.fastjson2.writer.ObjectWriterBaseModule$WriterAnnotationProcessor.getFieldInfo at line 311, then follow the related ObjectWriterProvider and ObjectWriterCreator calls in the stack trace. Reproduce the Retrofit2 request-body conversion with null and empty arrays, and verify that JSON serialization completes without the reported NullPointerException.

Written by the indexing model from the issue text.