use callPackage for merge-after-ci, nix-unit & tea-create-pr

pkgs/tea-create-pr/default.nix

@@ -1,26 +1,20 @@
-{
-  perSystem =
-    { pkgs
-    , ...
-    }:
-    let
-      name = builtins.baseNameOf ./.;
-      script = pkgs.writeShellApplication {
-        inherit name;
-        runtimeInputs = [
-          pkgs.bash
-          pkgs.coreutils
-          pkgs.git
-          pkgs.tea
-          pkgs.openssh
-        ];
-        text = ''
-          export EDITOR=${pkgs.vim}/bin/vim
-          bash ${./script.sh} "$@"
-        '';
-      };
-    in
-    {
-      packages.${name} = script;
-    };
+{ writeShellApplication
+, bash
+, coreutils
+, git
+, tea
+, openssh
+}:
+writeShellApplication {
+  name = "tea-create-pr";
+  runtimeInputs = [
+    bash
+    coreutils
+    git
+    tea
+    openssh
+  ];
+  text = ''
+    bash ${./script.sh} "$@"
+  '';
 }