chore(3p/sources): bump channels & overlays (2023-12-06)

* 3p/rust-crates: fix names of crate URLs to accommodate recent
  crates.io changes:

  https://blog.rust-lang.org/2023/10/27/crates-io-non-canonical-downloads.html

* 3p/rust-crates: fix comment describing what this is

* 3p/overlays: discard custom overrides of Nix 2.3: it's now
  maintained properly upstream

* users/wpcarro/emacs: disable doom themes package

Change-Id: Ic5def77319a0a55e78c8ffe05b9309d59784cfd9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10204
Reviewed-by: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>

users/wpcarro/emacs/default.nix

@@ -86,7 +86,8 @@ let
       diminish
       direnv
       dockerfile-mode
-      doom-themes
+      # TODO(wpcarro): broken since channel bump cl/10204
+      # doom-themes
       elisp-slime-nav
       elixir-mode
       elm-mode
@@ -261,5 +262,6 @@ in
     touch $out
   '';
 
-  meta.ci.targets = [ "check" ];
+  # TODO(wpcarro): commented out because of doom-themes breakage; cl/10204
+  # meta.ci.targets = [ "check" ];
 }