erlang: update default to OTP 27

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -18,6 +18,8 @@
 
 - The default PHP version has been updated to 8.3.
 
+- The default Erlang OTP version has been updated to 27.
+
 - `nixos-rebuild-ng`, a full rewrite of `nixos-rebuild` in Python, is available for testing. You can enable it by setting [system.rebuild.enableNg](options.html#opt-system.rebuild.enableNg) in your configuration (this will replace the old `nixos-rebuild`), or by adding `nixos-rebuild-ng` to your `environment.systemPackages` (in this case, it will live side-by-side with `nixos-rebuild` as `nixos-rebuild-ng`). It is expected that the next major version of NixOS (25.11) will enable `system.rebuild.enableNg` by default.
 - A `nixos-rebuild build-image` sub-command has been added.
 

pkgs/top-level/beam-packages.nix

@@ -20,7 +20,7 @@ in
 {
   beamLib = callPackage ../development/beam-modules/lib.nix { };
 
-  latestVersion = "erlang_25";
+  latestVersion = "erlang_27";
 
   # Each
   interpreters = {