gh-105708: 'V' could be case insensitive for IPvFuture hostnames (#105709)

gh-105708: 'V' could be case insensitive for IPvFuture hostnames (#105709)

* gh-105708: 'V' could be case insensitive for IPvFuture hostnames

* gh-105708: 'V' could be case insensitive for IPvFuture hostnames & checking empty hostnames

* 📜🤖 Added by blurb_it.

* Fix the Merge changing \z to \Z.

* Fixed the News Entry.

* Fix the lint.

---------

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Senthil Kumaran <senthil@python.org>