elisp-packages/manual-packages.nix: get rid of with

As related in https://nix.dev/anti-patterns/language#with-attrset-expression:

- Static analysis can’t reason about the code, because it would have to actually
  evaluate this file to see what variables are in scope;

- As soon as there are two with used, it’s not clear anymore from which the
  variables are coming from;

- Scoping rules around with are not intuitive. Examples:
  - https://github.com/NixOS/nix/issues/490
  - https://github.com/pikajude/nixpkgs/commit/eea78e554e03906524f87406bb3a17d5c5264029

pkgs/applications/editors/emacs/elisp-packages/manual-packages.nix

@@ -1,7 +1,10 @@
 { lib, pkgs }:
 
-self: with self; {
-
+self:
+let
+  inherit (pkgs) callPackage;
+in
+{
   agda-input = callPackage ./manual-packages/agda-input { };
 
   agda2-mode = callPackage ./manual-packages/agda2-mode { };
@@ -84,8 +87,8 @@ self: with self; {
   sunrise-commander = callPackage ./manual-packages/sunrise-commander { };
 
   # camelCase aliases for some of the kebab-case expressions above
-  colorThemeSolarized = color-theme-solarized;
-  emacsSessionManagement = session-management-for-emacs;
-  rectMark = rect-mark;
-  sunriseCommander = sunrise-commander;
+  colorThemeSolarized = self.color-theme-solarized;
+  emacsSessionManagement = self.session-management-for-emacs;
+  rectMark = self.rect-mark;
+  sunriseCommander = self.sunrise-commander;
 }