treewide: remove explicit gcc12Stdenv

pkgs/applications/editors/imhex/default.nix

···
 { lib
-, gcc12Stdenv
+, stdenv
 , cmake
 , llvm
 , fetchFromGitHub
···
   };
 
 in
-gcc12Stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   pname = "imhex";
   inherit version;
 

pkgs/applications/emulators/rpcs3/default.nix

···
-{ gcc12Stdenv, lib, fetchFromGitHub, wrapQtAppsHook, cmake, pkg-config, git
+{ lib, stdenv, fetchFromGitHub, wrapQtAppsHook, cmake, pkg-config, git
 , qtbase, qtquickcontrols, qtmultimedia, openal, glew, vulkan-headers, vulkan-loader, libpng
 , ffmpeg, libevdev, libusb1, zlib, curl, wolfssl, python3, pugixml, faudio, flatbuffers
 , sdl2Support ? true, SDL2
···
     sha256 = "0c3g30rj1y8fbd2q4kwlpg1jdy02z4w5ryhj3yr9051pdnf4kndz";
   };
 in
-gcc12Stdenv.mkDerivation {
+stdenv.mkDerivation {
   pname = "rpcs3";
   version = rpcs3Version;
 

pkgs/development/libraries/qcoro/default.nix

···
-{ stdenv
-, gcc12Stdenv
-, lib
+{ lib
+, stdenv
 , fetchFromGitHub
 , cmake
 , libpthreadstubs
···
 , wrapQtAppsHook
 }:
 
-gcc12Stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   pname = "qcoro";
   version = "0.9.0";
 

pkgs/top-level/all-packages.nix

···
     cairo = cairo.override { xcbSupport = true; };  };
 
   hyprland = callPackage ../applications/window-managers/hyprwm/hyprland {
-    stdenv = gcc12Stdenv;
     wlroots = pkgs.callPackage ../applications/window-managers/hyprwm/hyprland/wlroots.nix { };
     udis86 = pkgs.callPackage ../applications/window-managers/hyprwm/hyprland/udis86.nix { };
   };
···
 
   hyprland-share-picker = libsForQt5.callPackage ../applications/window-managers/hyprwm/xdg-desktop-portal-hyprland/hyprland-share-picker.nix { };
 
-  hyprpaper = callPackage ../applications/window-managers/hyprwm/hyprpaper {
-    stdenv = gcc12Stdenv;
-  };
+  hyprpaper = callPackage ../applications/window-managers/hyprwm/hyprpaper { };
 
   hyprpicker = callPackage ../applications/window-managers/hyprwm/hyprpicker { };
 
···
 
   lmdbxx = callPackage ../development/libraries/lmdbxx { };
 
-  lemon-graph = callPackage ../development/libraries/lemon-graph {
-    stdenv = if stdenv.isLinux then gcc12Stdenv else stdenv;
-  };
+  lemon-graph = callPackage ../development/libraries/lemon-graph { };
 
   levmar = callPackage ../development/libraries/levmar { };