doc/release-notes: add frr 10.0 BGP

Signed-off-by: Markus Theil <[email protected]>

nixos/doc/manual/release-notes/rl-2405.section.md

@@ -435,6 +435,8 @@ Use `services.pipewire.extraConfig` or `services.pipewire.configPackages` for Pi
 - `services.archisteamfarm` no longer uses the abbreviation `asf` for its state directory (`/var/lib/asf`), user and group (both `asf`). Instead the long name `archisteamfarm` is used.
   Configurations with `system.stateVersion` 23.11 or earlier, default to the old stateDirectory until the 24.11 release and must either set the option explicitly or move the data to the new directory.
 
+- `frr` was updated to 10.0, which introduces the default of `enforce-first-as` for BGP. Please disable again if needed.
+
 - `services.aria2.rpcSecret` has been replaced with `services.aria2.rpcSecretFile`.
   This was done so that secrets aren't stored in the world-readable nix store.
   To migrate, you will have to create a file with the same exact string, and change