_389ds-base: mark as broken

Doesn't build with glibc 2.39. There's a potential fix documented in
https://github.com/389ds/389-ds-base/issues/5332, but the package is too
old for the patch to apply, so I'll mark it as broken for now and leave
it to the maintainer to update & fix.

pkgs/servers/ldap/389/default.nix

@@ -141,5 +141,9 @@ stdenv.mkDerivation rec {
     license = licenses.gpl3Plus;
     platforms = platforms.linux;
     maintainers = [ maintainers.ners ];
+    # https://hydra.nixos.org/build/249763145, doesn't build since glibc 2.39.
+    # Potential fix is documented in https://github.com/389ds/389-ds-base/issues/5332,
+    # but it doesn't apply here.
+    broken = true;
   };
 }