move flake-parts into pkgs or toplevel

pkgs/merge-after-ci/default.nix

@@ -0,0 +1,27 @@
+{
+  perSystem =
+    { pkgs
+    , self'
+    , ...
+    }:
+    let
+      name = builtins.baseNameOf ./.;
+      script = pkgs.writeShellApplication {
+        inherit name;
+        runtimeInputs = [
+          pkgs.bash
+          pkgs.coreutils
+          pkgs.git
+          pkgs.tea
+          pkgs.openssh
+          self'.packages.tea-create-pr
+        ];
+        text = ''
+          bash ${./script.sh} "$@"
+        '';
+      };
+    in
+    {
+      packages.${name} = script;
+    };
+}

pkgs/merge-after-ci/script.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+remoteName="${1:-origin}"
+targetBranch="${2:-main}"
+shift && shift
+tea-create-pr "$remoteName" "$targetBranch" --assignees clan-bot "$@"