use `Buffer.into_mutable` to reuse the allocation if possible in `take_n_true`

[haohuaijin]

Since this takes self by value, we could potentially use Buffer.into_mutable to reuse the allocation if possible

Originally posted by @alamb in #9823 (comment)

[Rich-T-kid]

@haohuaijin does #9823 close this?

[alamb]

No, I think it inspired this issue:

https://github.com/apache/arrow-rs/pull/9823/changes#r3506852519