chore(3p/sources): bump nixpkgs channels & overlays

* 3p/buzz: delete package

  This is unused, old, and uses an insecure version of OpenSSL which
  broke eval.

* 3p/overlays: remove nvd patch

  Newer versions of nvd are compatible with Nix 2.3 by default.

* users/grfn/system/home: remove explicit rust-analyser package

  This conflicts with `rustup`, causing eval failures, as the wrapper
  seems to now be included in `rustup` by default.

* users/grfn/system: temporarily disable ISO builds

  They were broken upstream in nixpkgs by a change to stdenv/setup.sh,
  being fixed in https://github.com/NixOS/nixpkgs/pull/234883

Change-Id: I0eea99ec98f4e73e615c012ffae1d0e37122e73b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8585
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>

users/grfn/system/home/modules/development/rust.nix

@@ -7,7 +7,6 @@ in
 
   home.packages = with pkgs; [
     rustup
-    rust-analyzer
     cargo-edit
     cargo-expand
     cargo-rr

users/grfn/system/system/default.nix

@@ -30,7 +30,10 @@ rec {
 
   yerenSystem = (depot.ops.nixos.nixosFor yeren).system;
 
-  iso = import ./iso.nix args;
+  # TODO(grfn): reenable after
+  # https://github.com/NixOS/nixpkgs/pull/234883 has propagated
+  # through to our channel
+  # iso = import ./iso.nix args;
 
   meta.ci.targets = [
     "mugwumpSystem"