feat!: remove vimballs (#22402)

Vimball is an outdated feature that is rarely used these days. It is not
a maintenance burden on its own, but it is nonetheless dead weight and
something we'd need to tell users to ignore when they inevitably ask
what it is.

See: https://github.com/neovim/neovim/pull/21369#issuecomment-1347615173

runtime/doc/news.txt

@@ -39,6 +39,9 @@ The following deprecated functions or APIs were removed.
 
 • ...
 
+• Vimball support is removed.
+  - :Vimuntar command removed.
+
 ==============================================================================
 DEPRECATIONS                                                *news-deprecations*
 

runtime/doc/pi_tar.txt

@@ -33,23 +33,6 @@ Copyright 2005-2017:					*tar-copyright*
    also write to the file.  Currently, one may not make a new file in
    tar archives via the plugin.
 
-						*:Vimuntar*
-   VIMUNTAR~
-
-   :Vimuntar [vimhome]
-
-	This command copies, if necessary, the tarball to the .vim or vimfiles
-	directory using the first writable directory in the |'runtimepath'|
-	when no [vimhome] is specified.  Otherwise, the [vimhome] argument
-	allows the user to specify that directory, instead.
-
-	The copy is done using the command in *g:tar_copycmd* , which is >
-		cp   for cygwin, unix, macunix
-		copy for windows (32, 95, 64, 16)
-<	The extraction is done with the command specified with
-	*g:tar_extractcmd* , which by default is >
-		"tar -xf"
-<
 						*:TarDiff*
    DIFFERENCING SUPPORT~
 

runtime/doc/usr_05.txt

@@ -190,27 +190,22 @@ The ":map" command (with no arguments) lists your current mappings.  At
 least the ones for Normal mode.  More about mappings in section |40.1|.
 
 ==============================================================================
-*05.4*	Adding a package			*add-package* *vimball-install*
+*05.4*	Adding a package					*add-package*
+
+You may use |:packadd| to enable packages on demand. This is useful for plugins
+you want to enable only sometimes. To enable `example_package`, use the
+following command: >
+       packadd example_package
+
+That's all!  Now you can find help about this plugin: >
+       :help example_package
+
+This works, because when `:packadd` loaded the plugin it also added the
+package directory in 'runtimepath', so that the help file can be found.
 
 A package is a set of files that you can add to Vim.  There are two kinds of
 packages: optional and automatically loaded on startup.
 
-The Vim distribution comes with a few packages that you can optionally use.
-For example, the vimball plugin.  This plugin supports creating and using
-vimballs (self-installing Vim plugin archives).
-
-To start using the vimball plugin, add one line to your vimrc file: >
-	packadd vimball
-
-That's all!  You can also type the command to try it out.  Now you can find
-help about this plugin: >
-	:help vimball
-
-This works, because when `:packadd` loaded the plugin it also added the
-package directory in 'runtimepath', so that the help file can be found.  The
-tags for vimball's help are already created.  If you need to generate the help
-tags for a package, see the `:helptags` command.
-
 You can find packages on the Internet in various places.  It usually comes as
 an archive or as a repository.  For an archive you can follow these steps:
 	1. create the package directory: >

runtime/doc/vim_diff.txt

@@ -573,6 +573,7 @@ Commands:
   :cscope
   :lcscope
   :scscope
+  :Vimuntar
 
 Compile-time features:
   Emacs tags support
@@ -764,5 +765,8 @@ Hardcopy:
   `:hardcopy` was removed. Instead, use `:TOhtml` and print the resulting HTML
   using a web browser or some other HTML viewer.
 
+Bundled plugins:
+  vimball                                                             *vimball*
+
 ==============================================================================
  vim:tw=78:ts=8:sw=2:et:ft=help:norl: