akku: pin Guile 3.0.10

This prevents a breakage with the upcoming Guile 3.0.11.

pkgs/tools/package-management/akku/akku.nix

@@ -1,14 +1,26 @@
 {
   lib,
   stdenv,
+  fetchurl,
   fetchFromGitLab,
   autoreconfHook,
   pkg-config,
   git,
-  guile,
+  guile_3_0,
   curl,
   nix-update-script,
 }:
+let
+  # Akku currently breaks starting with Guile 3.0.11.
+  # So we pin Guile 3.0.10 for now.
+  # https://hydra.nixos.org/build/319214800/nixlog/1/tail
+  guile_3_0_10 = guile_3_0.overrideAttrs {
+    src = fetchurl {
+      url = "mirror://gnu/guile/guile-3.0.10.tar.xz";
+      sha256 = "sha256-vXFoUX/VJjM0RtT3q4FlJ5JWNAlPvTcyLhfiuNjnY4g=";
+    };
+  };
+in
 stdenv.mkDerivation rec {
   pname = "akku";
   version = "1.1.0-unstable-2025-11-08";
@@ -27,7 +39,7 @@ stdenv.mkDerivation rec {
 
   # akku calls curl commands
   buildInputs = [
-    guile
+    guile_3_0_10
     curl
     git
   ];