Add `delete_files`

### Feature Request / Improvement

Hello All,

First of all, apologies as I am not very experienced with PyIceberg.

I currently have a Java application that "manually" updates table metadata and can add new files if they don't exist and replace older files if they already do. This guarantees that, as long as the file names are fixed, I should not have duplicates.

In Java, I use [deleteFile](https://iceberg.apache.org/javadoc/0.13.1/org/apache/iceberg/DeleteFiles.html#deleteFile-java.lang.CharSequence-) and then [addFile](https://iceberg.apache.org/javadoc/0.13.1/org/apache/iceberg/OverwriteFiles.html#addFile-org.apache.iceberg.DataFile-).

In PyIceberg, I can [Add Files](https://py.iceberg.apache.org/api/#add-files), but I don't see options to "Delete Files" or overwrite.

Is `delete_files()` a feature that you could add?

从 PyIceberg 现有的 Add Files API 开始，并将其行为与链接的 Java DeleteFiles 和 OverwriteFiles API 进行比较。定义支持的 delete_files 或 overwrite 语义，并验证已完成的功能能够让调用方移除或替换现有数据文件，而不会创建重复项。

由索引模型根据 Issue 内容生成。