Remove redundant requires of 'button'

* lisp/apropos.el:
* lisp/emacs-lisp/cl-print.el:
* lisp/emacs-lisp/debug.el:
* lisp/emacs-lisp/ert.el:
* lisp/emacs-lisp/shadow.el:
* lisp/facemenu.el:
* lisp/help-mode.el:
* lisp/man.el:
* lisp/progmodes/etags.el:
* lisp/textmodes/bibtex.el:
* lisp/woman.el: Don't require 'button'; it is preloaded since version
23.1.

lisp/apropos.el

@@ -56,8 +56,6 @@
 
 ;;; Code:
 
-(require 'button)
-
 (defgroup apropos nil
   "Apropos commands for users and programmers."
   :group 'help

lisp/emacs-lisp/cl-print.el

@@ -33,8 +33,6 @@
 
 ;;; Code:
 
-(require 'button)
-
 (defvar cl-print-readably nil
   "If non-nil, try and make sure the result can be `read'.")
 

lisp/emacs-lisp/debug.el

@@ -29,7 +29,6 @@
 
 (require 'cl-lib)
 (require 'backtrace)
-(require 'button)
 
 (defgroup debugger nil
   "Debuggers and related commands for Emacs."

lisp/emacs-lisp/ert.el

@@ -58,7 +58,6 @@
 ;;; Code:
 
 (require 'cl-lib)
-(require 'button)
 (require 'debug)
 (require 'backtrace)
 (require 'easymenu)

lisp/emacs-lisp/shadow.el

@@ -183,7 +183,6 @@ See the documentation for `list-load-path-shadows' for further information."
 	buffer-read-only t))
 
 ;; TODO use text-properties instead, a la dired.
-(require 'button)
 (define-button-type 'load-path-shadows-find-file
   'follow-link t
 ;;  'face 'default

lisp/facemenu.el

@@ -86,8 +86,7 @@
 ;;; Code:
 
 (eval-when-compile
-  (require 'help)
-  (require 'button))
+  (require 'help))
 
 ;; Global bindings:
 (define-key global-map [C-down-mouse-2] 'facemenu-menu)

lisp/help-mode.el

@@ -29,7 +29,6 @@
 
 ;;; Code:
 
-(require 'button)
 (require 'cl-lib)
 (eval-when-compile (require 'easymenu))
 

lisp/man.el

@@ -90,7 +90,6 @@
 
 (require 'ansi-color)
 (require 'cl-lib)
-(require 'button)
 
 (defgroup man nil
   "Browse UNIX manual pages."

lisp/progmodes/etags.el

@@ -34,7 +34,6 @@
 ;;   prefixes but somewhere within the name.
 
 (require 'ring)
-(require 'button)
 (require 'xref)
 (require 'fileloop)
 

lisp/textmodes/bibtex.el

@@ -40,8 +40,6 @@
 
 ;;; Code:
 
-(require 'button)
-
 
 ;; User Options:
 

lisp/woman.el

@@ -404,7 +404,6 @@
 (make-obsolete-variable 'woman-version nil "28.1")
 
 (require 'man)
-(require 'button)
 (define-button-type 'WoMan-xref-man-page
   :supertype 'Man-abstract-xref-man-page
   'func (lambda (arg)