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

overrides/default.nix

@@ -1,28 +1,13 @@
 # This file is used to move things from nested attribute sets to the
 # top-level.
-{ pkgs, ... }:
+{ depot, ... }:
 
 {
-  buildGo = pkgs.nix.buildGo;
-
-  # These packages must be exposed at the top-level for compatibility
-  # with Nixery.
-  inherit (pkgs.third_party)
-    bashInteractive
-    cacert
-    coreutils
-    iana-etc
-    jq
-    moreutils
-    nano
-    openssl
-    runCommand
-    symlinkJoin
-    writeText;
+  buildGo = depot.nix.buildGo; # TODO(tazjin): remove this
 
   # These packages must be exposed for compatibility with buildGo.
   #
   # Despite buildGo being tracked in this tree, I want it to be possible
   # for external users to import it with the default nixpkgs layout.
-  inherit (pkgs.third_party) go ripgrep;
+  inherit (depot.third_party) go ripgrep;
 }