fix version of disko

configuration.nix

@@ -9,8 +9,8 @@
     [ # Include the results of the hardware scan.
       ./hardware-configuration.nix
       "${builtins.fetchTarball {
-        url = "https://github.com/nix-community/disko/archive/master.tar.gz";
+        url = "https://github.com/nix-community/disko/archive/refs/tags/v1.6.1.tar.gz";
-        sha256 = "1z9x5jig1mcn41vcqlb3nld91lfdfx4nfwb23k4zjy4yfh59a99p";
+        sha256 = "09yvxf1cbkwv6lncnfcnkj83jm5qs812q6dvvvq40n7wg4kl1gpj";
       }}/module.nix"
       ./disko.nix
     ];