switch from alejandra -> nixpkgs-fmt

alejandra has someone questionable choices for formatting that no one would apply to there code if they would format manually.
nixpkgs-fmt seems to produce more readable results.

templates/python-project/flake-module.nix

@@ -1,10 +1,12 @@
 {
-  perSystem = {pkgs, ...}: let
-    pyproject = builtins.fromTOML (builtins.readFile ./pyproject.toml);
-    name = pyproject.project.name;
-    package = pkgs.callPackage ./default.nix {};
-  in {
-    # packages.${name} = package;
-    checks.python-template = package.tests.check;
-  };
+  perSystem = { pkgs, ... }:
+    let
+      pyproject = builtins.fromTOML (builtins.readFile ./pyproject.toml);
+      name = pyproject.project.name;
+      package = pkgs.callPackage ./default.nix { };
+    in
+    {
+      # packages.${name} = package;
+      checks.python-template = package.tests.check;
+    };
 }