Allow overriding partitioning scripts

lib/modules/partition/disks.nix

@@ -64,7 +64,6 @@
           script = mkOption {
             type = types.str;
             description = "The script for formatting the disk.";
-            internal = true;
           };
         };
 
@@ -195,7 +194,7 @@
               '' else ""}
             '';
 
-          script = ''
+          script = lib.mkDefault ''
             function partition() {
               ${if (!config.wipe) then cleanup else ""}
 
@@ -306,9 +305,8 @@
           };
 
           script = mkOption {
-            type = types.lines;
+            type = types.str;
             description = "The script for partitioning the system's disks.";
-            internal = true;
           };
         };
       };
@@ -317,7 +315,7 @@
     config = {
       valhalla = {
         partition = {
-          script =
+          script = lib.mkDefault (
             let
               cfg = config.valhalla.partition;
               inherit (cfg) os rootDir;
@@ -363,7 +361,7 @@
                 mountScript
                 swapScript
               ]
-            );
+            ));
         };
       };
     };