[OpenAPI] Add lfs flag to the metadata of entries

### Feature Description

https://docs.gitea.com/api/1.20/#tag/repository/operation/repoGetContents

With the getContents api, I can get a list of entries at certain path. However I couldn't tell which entries are tracked by lfs and which are not. It'd be ideal if an `lfs` flag is added to each entry indicating that whether it is tracked by lfs.

### Screenshots

_No response_