runtime: don't execute external commands when loading ftplugins

This is a followup to 816fbcc262687b81fc46f82f7bbeb1453addfe0c (patch
9.0.1833: [security] runtime file fixes)

It basically disables that external commands are run on loading of the
filetype plugin, **unless** the user has set the `g:plugin_exec = 1`
global variable in their configuration or for a specific filetype the
variable g:<filetype>_exec=1.

There are a few more plugins, that may execute system commands like
debchangelog, gitcommit, sh, racket, zsh, ps1 but those do at least
do not run those commands by default during loading of the filetype plugin
(there the command is mostly run as convenience for auto-completion or
to provide documentation lookup).

closes: vim/vim#13034

https://github.com/vim/vim/commit/f7ac0ef5098856bedca26e7073594a407c05636f

Co-authored-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Tim Pope <vim@tpope.org>

runtime(ftplugin): allow to exec if curdir is in PATH

In case the current directory is present as valid $PATH entry, it is OK
to call the program from it, even if vim curdir is in that same
directory.

(Without that patch, for instance, you will not be able to open .zip
files while your current directory is /bin)

closes: vim/vim#13027

https://github.com/vim/vim/commit/67c951df4c95981c716eeedb1b102d9668549e65

Co-authored-by: Anton Sharonov <anton.sharonov@gmail.com>

runtime: Fix problem of checking wrong cwd for ruby ftplugin (vim/vim#13026)

https://github.com/vim/vim/commit/282a94be990fc1ee5be46548bf7241b583d48972

Co-authored-by: Anton Sharonov (ant0sha) <109120102+ant0sha@users.noreply.github.com>
Co-authored-by: Anton Sharonov <anton.sharonov@gmail.com>

runtime(ruby): Update syntax, indent and ftplugin files

While making changes to the ruby ftplugin, slightly change the exepath()
conditional from patch 9.0.1833 and move it after the :cd invocation.

closes: 12981
closes: 12994

https://github.com/vim/vim/commit/da16a1b471aa717f58909cc6531cb6dbbff14d22

Co-authored-by: Doug Kearns <dougkearns@gmail.com>
Co-authored-by: Tim Pope <code@tpope.net>

Problem:  runtime files may execute code in current dir
Solution: only execute, if not run from current directory

The perl, zig and ruby filetype plugins and the zip and gzip autoload
plugins may try to load malicious executable files from the current
working directory.  This is especially a problem on windows, where the
current directory is implicitly in your $PATH and windows may even run a
file with the extension `.bat` because of $PATHEXT.

So make sure that we are not trying to execute a file from the current
directory. If this would be the case, error out (for the zip and gzip)
plugins or silently do not run those commands (for the ftplugins).

This assumes, that only the current working directory is bad. For all
other directories, it is assumed that those directories were
intentionally set to the $PATH by the user.

https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c

Co-authored-by: Christian Brabandt <cb@256bit.org>

Update runtime files
https://github.com/vim/vim/commit/46eea444d992c2ae985cabb775a5d283f8e16df3

Skip repeat.txt as it only has vim9-specific changes.

* vim-patch:4d8f476176ea

Update runtime files
https://github.com/vim/vim/commit/4d8f476176eadfc745bcb8e143460029048f858d

skip nsis/README.txt
skip doc/vim9.txt
skip src/nvim/po/it.po

Update a few runtime files.
https://github.com/vim/vim/commit/2ed639abdc4000436115f378e28320b7bee38a6e

Update runtime files.
https://github.com/vim/vim/commit/d09091d4955c5f41de69928f2db85611ed54ed23

Updated runtime files.  Remove version checks for Vim older than 6.0.

https://github.com/vim/vim/commit/89bcfda6834aba724d12554a34b9ed49f5789fd5