chore: set up daily flake update with Hercules CI (#643)

Author: bbjubjub2494

flake.lock

@@ -27,6 +27,13 @@
     flake-utils.url = "github:numtide/flake-utils";
     flake-utils.inputs.systems.follows = "systems";
 
+    # ci
+    hercules-ci-effects = {
+      url = "github:hercules-ci/hercules-ci-effects";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-parts.follows = "flake-parts";
+    };
+
     # utils
     systems.url = "github:nix-systems/default";
     devshell = {
@@ -55,11 +62,14 @@
     {
       imports = [
         inputs.devshell.flakeModule
+        inputs.hercules-ci-effects.flakeModule
         inputs.treefmt-nix.flakeModule
         ./mkdocs.nix
         ./modules
         ./pkgs
+        ./hercules-ci.nix
       ];
+
       systems = import systems;
       perSystem = {
         config,

flake.nix

@@ -0,0 +1,19 @@
+{
+  inputs,
+  lib,
+  ...
+}: {
+  # configuration for the Hercules CI flake update effect
+  # https://flake.parts/options/hercules-ci-effects.html#opt-hercules-ci.flake-update.enable
+  hercules-ci.flake-update = {
+    enable = true;
+    # runs every day at midnight UTC
+    when.hour = 0;
+  };
+
+  # disable the default job since buildbot already builds everything
+  herculesCI.onPush.default.outputs = lib.mkForce {
+    # use hello as a dummy output to get the checkmark
+    inherit (inputs.nixpkgs-unstable.legacyPackages.x86_64-linux) hello;
+  };
+}