chore: Rename pkgs->depot in all Nix file headers

fun/amsterdump/default.nix

@@ -1,12 +1,12 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
-pkgs.buildGo.program {
+depot.nix.buildGo.program {
   name = "amsterdump";
   srcs = [
     ./main.go
   ];
 
-  deps = with pkgs.third_party; map (p: p.gopkg) [
+  deps = with depot.third_party; map (p: p.gopkg) [
     # gopkgs."golang.org".x.oauth2.google
     gopkgs."googlemaps.github.io".maps
   ];

fun/aoc2019/default.nix

@@ -1,7 +1,7 @@
 # Solutions for Advent of Code 2019, written in Emacs Lisp.
 #
 # For each day a new file is created as "solution-day$n.el".
-{ pkgs, ... }:
+{ depot, ... }:
 
 let
   inherit (builtins) attrNames filter head listToAttrs match readDir;
@@ -13,7 +13,7 @@ let
   solutionFiles = filter (e: dir."${e}" == "regular" && isSolution e) (attrNames dir);
   solutions = map (f: let day = getDay f; in {
     name = day;
-    value = pkgs.writeElispBin {
+    value = depot.writeElispBin { # TODO(tazjin): move writeElispBin to depot.nix
       name = "aoc2019";
       deps = p: with p; [ dash s ht ];
       src = ./. + ("/" + f);

fun/gemma/default.nix

@@ -1,8 +1,8 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
 let
-  inherit (pkgs) elmPackages;
-  inherit (pkgs.third_party) cacert iana-etc libredirect stdenv runCommandNoCC;
+  inherit (depot) elmPackages;
+  inherit (depot.third_party) cacert iana-etc libredirect stdenv runCommandNoCC writeText;
 
   frontend = stdenv.mkDerivation {
     name = "gemma-frontend.html";
@@ -26,17 +26,17 @@ let
     '';
   };
 
-  injectFrontend = pkgs.writeText "gemma-frontend.lisp" ''
+  injectFrontend = writeText "gemma-frontend.lisp" ''
     (in-package :gemma)
     (setq *static-file-location* "${runCommandNoCC "frontend" {} ''
       mkdir -p $out
       cp ${frontend} $out/index.html
     ''}/")
   '';
-in pkgs.nix.buildLisp.program {
+in depot.nix.buildLisp.program {
   name = "gemma";
 
-  deps = with pkgs.third_party.lisp; [
+  deps = with depot.third_party.lisp; [
     cl-json
     cl-prevalence
     hunchentoot

fun/quinistry/default.nix

@@ -1,6 +1,6 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
-pkgs.buildGo.program {
+depot.nix.buildGo.program {
   name = "quinistry";
   srcs = [
     ./const.go

fun/watchblob/default.nix

@@ -1,13 +1,13 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
-pkgs.buildGo.program {
+depot.nix.buildGo.program {
   name = "watchblob";
   srcs = [
     ./main.go
     ./urls.go
   ];
 
-  deps = with pkgs.third_party; [
+  deps = with depot.third_party; [
     gopkgs."golang.org".x.crypto.ssh.terminal.gopkg
   ];
 }

fun/wcl/default.nix

@@ -1,13 +1,13 @@
-{ pkgs, ... }:
+{ depot, ... }:
 
-pkgs.nix.buildLisp.program {
+depot.nix.buildLisp.program {
   name = "wc";
 
   srcs = [
     ./wc.lisp
   ];
 
-  deps = with pkgs.third_party.lisp; [
+  deps = with depot.third_party.lisp; [
     unix-opts
     iterate
   ];