TUI: exepath is set to PATH twice on Windows

[erw7]

Problem

exepath is set to PATH twice.

Perhaps exepath was added in tui and more exepath was added in server. The design of #18375 is wrong. The TUI and server code should be separated. Ad hoc code that branches conditional on ui_client_channel_id should not be written.
Cc: @bfredl

Steps to reproduce

set PATH=C:\Windows;C:\Windows\System32
nvim --clean
:echo $PATH
C:\Windows;C:\Windows\System32;C:\Neovim\bin;C:\Neovim\bin " If neovim is located at C:\Neovim\bin.

Expected behavior

exepath is set to PATH only once.

Neovim version (nvim -v)

cce7362 or later

Vim (not Nvim) behaves the same?

N/A

Operating system/version

Windows

Terminal name/version

N/A

$TERM environment variable

N/A

Installation

zip of release page

[bfredl]

The design of #18375 is wrong.. The TUI and server code should be separated.

That's... exactly what it already does. Also see follow up PR:s which disentangles them further.

Ad hoc code that branches conditional on ui_client_channel_id should not be written.

Feel free to write other sorts of code to solve this particular issue 👍