Merge pull request #234639 from Atemu/rl-buildFHSEnvBubblewrap-migration

rl-2305: mention buildFHSEnv switch to bubblewrap

nixos/doc/manual/release-notes/rl-2305.section.md

@@ -194,6 +194,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - `graylog` has been updated to version 5, which can not be upgraded directly from the previously packaged version 3.3. If you had installed the previously packaged version 3.3, please follow the [upgrade path](https://go2docs.graylog.org/5-0/upgrading_graylog/upgrade_path.htm) from 3.3 to 4.0 to 4.3 to 5.0.
 
+- `buildFHSUserEnv` is now called `buildFHSEnv` and uses FlatPak's Bubblewrap sandboxing tool rather than Nixpkgs' own chrootenv. The old chrootenv-based implemenation is still available via `buildFHSEnvChrootenv` but is considered deprecated and will be removed when the remaining uses inside Nixpkgs have been migrated. If your FHSEnv-wrapped application misbehaves when using the new bubblewrap implementation, please create an issue in Nixpkgs.
+
 - `nushell` has been updated to at least version 0.77.0, which includes potential breaking changes in aliases. The old aliases are now available as `old-alias` but it is recommended you migrate to the new format. See [Reworked aliases](https://www.nushell.sh/blog/2023-03-14-nushell_0_77.html#reworked-aliases-breaking-changes-kubouch).
 
 - `gajim` has been updated to version 1.7.3 which has disabled legacy ciphers. See [changelog for version 1.7.0](https://dev.gajim.org/gajim/gajim/-/releases/1.7.0).