doc: add release note about xxd now being provided by tinyxxd ins…

…tead of `vim.xxd`

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -417,6 +417,8 @@
 
 - The `shadowstack` hardening flag has been added, though disabled by default.
 
+- `xxd` is now provided by the `tinyxxd` package, rather than `vim.xxd`, to reduce closure size and vulnerability impact. Since it has the same options and semantics as Vim's `xxd` utility, there is no user impact. Vim's `xxd` remains available as the `vim.xxd` package.
+
 - `restic` module now has an option for inhibiting system sleep while backups are running, defaulting to off (not inhibiting sleep), available as [`services.restic.backups.<name>.inhibitsSleep`](#opt-services.restic.backups._name_.inhibitsSleep).
 
 - Support for *runner registration tokens* has been [deprecated](https://gitlab.com/gitlab-org/gitlab/-/issues/380872)