pkgs/nixfiles: add script that updates flake inputs and pushes it to upstream

pkgs/nixfiles/default.nix

@@ -0,0 +1,10 @@
+{ pkgs, ... }:
+
+pkgs.writeShellApplication {
+  name = "nixfiles-updated-inputs.sh";
+  text = builtins.readFile ./nixfiles-updated-inputs.sh;
+  runtimeInputs = [
+    pkgs.git
+  ];
+}
+

pkgs/nixfiles/nixfiles-updated-inputs.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+NOW="$(date --utc --iso-8601=minutes)"
+
+git fetch origin master
+git checkout updated-inputs
+git merge -s ort -X theirs origin/master -m "Update from master ${NOW}"
+nix flake update
+git add flake.lock
+git commit -m "Flake update ${NOW}" || true
+git push origin updated-inputs