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?

PyIceberg の既存の Add Files API から始め、リンクされている Java の DeleteFiles API および OverwriteFiles API とその動作を比較します。サポートする delete_files または overwrite のセマンティクスを定義し、完成した機能によって呼び出し元が重複を作成せずに既存のデータファイルを削除または置換できることを確認します。

索引モデルが issue の本文から書いたものです。