emacs: remove custom emacsPackages

We can now directly use the existing package set since it supports
overrides.

modules/programs/emacs.nix

@@ -6,11 +6,7 @@ let
 
   cfg = config.programs.emacs;
 
-  # Copied from all-packages.nix, with modifications to support
-  # overrides.
-  emacsPackages = let epkgs = pkgs.emacsPackagesFor cfg.package;
-  in epkgs.overrideScope' cfg.overrides;
-
+  emacsPackages = cfg.package.pkgs.overrideScope' cfg.overrides;
   emacsWithPackages = emacsPackages.emacsWithPackages;
 
   createConfPackage = epkgs:

tests/modules/services/emacs/emacs-service-27.nix

@@ -8,9 +8,9 @@ with lib;
       (self: super: rec {
         emacs = pkgs.writeShellScriptBin "dummy-emacs-27.2" "" // {
           outPath = "@emacs@";
+          pkgs =
+            makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
         };
-        emacsPackagesFor = _:
-          makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
       })
     ];
 

tests/modules/services/emacs/emacs-service-28.nix

@@ -8,9 +8,9 @@ with lib;
       (self: super: rec {
         emacs = pkgs.writeShellScriptBin "dummy-emacs-28.0.5" "" // {
           outPath = "@emacs@";
+          pkgs =
+            makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
         };
-        emacsPackagesFor = _:
-          makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
       })
     ];
 

tests/modules/services/emacs/emacs-socket-27.nix

@@ -10,9 +10,9 @@ in {
       (self: super: rec {
         emacs = pkgs.writeShellScriptBin "dummy-emacs-27.2" "" // {
           outPath = "@emacs@";
+          pkgs =
+            makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
         };
-        emacsPackagesFor = _:
-          makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
       })
     ];
 

tests/modules/services/emacs/emacs-socket-28.nix

@@ -10,9 +10,9 @@ in {
       (self: super: rec {
         emacs = pkgs.writeShellScriptBin "dummy-emacs-28.0.5" "" // {
           outPath = "@emacs@";
+          pkgs =
+            makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
         };
-        emacsPackagesFor = _:
-          makeScope super.newScope (_: { emacsWithPackages = _: emacs; });
       })
     ];