Repacment API for capabilities such as `list_has_content_length` etc.

@Xuanwo @yihong0618 GreptimeDB used `list_has_content_length` to determine whether to call `stat` again:

https://github.com/GreptimeTeam/greptimedb/blob/d774996e89648dbdf25326cc8440b51847095abb/src/object-store/src/layers/lru_cache/read_cache.rs#L163

Since it’s been removed, is there a replacement API?

Looks like it's always true, so maybe I can just remove this checking.

Thank you.

_Originally posted by @killme2008 in https://github.com/apache/opendal/issues/6313#issuecomment-3213239065_

Start with the referenced GreptimeDB call in src/object-store/src/layers/lru_cache/read_cache.rs around line 163 and determine which OpenDAL capability API it depended on. Review the current OpenDAL capability API and its removal context; done means identifying a supported replacement or documenting that the check can be removed.

Written by the indexing model from the issue text.