Ubuntu is based of Debian testing. You can verify this by comparing the versions of neovim available on the repos.

Debian[1]:

> trixie (stable) (editors): heavily refactored vim fork

> 0.10.4-8: amd64 arm64 armel armhf i386 ppc64el riscv64 s390x

> forky (testing) (editors): heavily refactored vim fork

> 0.12.4-1: amd64 arm64 armhf i386 loong64 ppc64el riscv64 s390x

Ubuntu[2]:

> stonking (26.10) (editors): heavily refactored vim fork [universe]

> 0.12.4-1: amd64 arm64 armhf ppc64el riscv64 s390x

I use Debian stable myself and build neovim from source for this specific reason.

[1]: https://packages.debian.org/search?keywords=neovim

[2]: https://packages.ubuntu.com/search?keywords=neovim&searchon=...