gnu: emacs-minimal: Drop meaningless input.

The search for guix-emacs.el has already been inlined into a phase shared
by all emacs variants.

* gnu/packages/emacs.scm (emacs-minimal)[inputs]: Remove "emacs/guix-emacs.el".

gnu/packages/emacs.scm

@@ -376,10 +376,7 @@ GTK and also enables xwidgets.")))
             (delete 'restore-emacs-pdmp)
             (delete 'strip-double-wrap)))))
     (inputs
-     (list (search-auxiliary-file "emacs/guix-emacs.el")
-           ncurses
-           coreutils
-           gzip))
+     (list ncurses coreutils gzip))
     (native-inputs
      (list autoconf pkg-config))))