bump nixos; add timezone secret; add alejandra; reconfigure nix for build testing

nix/sources.nix

@@ -8,7 +8,8 @@ let
   in
     if spec.builtin or true
     then
-      builtins_fetchurl {
+      builtins_fetchurl
+      {
         inherit (spec) url sha256;
         name = name';
       }
@@ -23,7 +24,8 @@ let
   in
     if spec.builtin or true
     then
-      builtins_fetchTarball {
+      builtins_fetchTarball
+      {
         name = name';
         inherit (spec) url sha256;
       }
@@ -54,9 +56,11 @@ let
       emptyArgWithWarning =
         if submodules == true
         then
-          builtins.trace (''The niv input "${name}" uses submodules ''
+          builtins.trace
+          (''The niv input "${name}" uses submodules ''
             + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "
-            + "does not support them") {}
+            + "does not support them")
+          {}
         else {};
     in
       if nixSupportsSubmodules
@@ -100,7 +104,8 @@ let
   mkPkgs = sources: system: let
     sourcesNixpkgs =
       import
-      (builtins_fetchTarball {inherit (sources.nixpkgs) url sha256;}) {
+      (builtins_fetchTarball {inherit (sources.nixpkgs) url sha256;})
+      {
         inherit system;
       };
     hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
@@ -220,7 +225,8 @@ let
 
   # Create the final "sources" from the config
   mkSources = config:
-    mapAttrs (name: spec:
+    mapAttrs
+    (name: spec:
       if builtins.hasAttr "outPath" spec
       then
         abort