feat: replace Reference::peel_to_id_in_place_packed

[cruessler]

This is hopefully the last follow-up to #2163 and #2171. It renames the last remaining method that still had an in_place infix, gix::reference::Reference::peel_to_id_in_place_packed, so that now all in_place methods that deal with references have been deprecated.

Note that there are a few other methods that still have an in_place infix or suffix, but are not related to references, such as gix::remote::url::rewrite::Rewrite::rewrite_url_in_place.

Also, I updated a couple of doc comments that were still referring to deprecated in_place methods to refer to the new methods instead.

[Byron]

This is wonderful, thanks a lot!

I particularly like how it removes … as it's always inconsistent, and how one commit is used to change two crates, while matching well enough for both.