chore(packages): Remove unused vulkan-hdr-layer package

The vulkan-hdr-layer package was not used anywhere in the configuration.
Removing it to reduce maintenance burden.

packages/default.nix

@@ -1,6 +1,5 @@
 { pkgs, ... }:
 {
-  vulkanHDRLayer = pkgs.callPackage ./vulkan-hdr-layer {};
   tea-rbw = pkgs.callPackage ./tea-rbw {};
   app-launcher-server = pkgs.callPackage ./app-launcher-server {};
   claude-code = pkgs.callPackage ./claude-code {};