bug#62407: 30.0.50; The command to run elixir-ls on Windows is `language_server.bat`

[牟 桐]

> 
>    ((elixir-mode elixir-ts-mode heex-ts-mode)
>     . ,(if (and (fboundp 'w32-shell-dos-semantics)
>                 (w32-shell-dos-semantics))        
>            '("language_server.bat")        
>          '("language_server.sh")))         
> 
> 
> 

BTW, elixir's lsp installed by brew on Mac is `elixir-ls`, a soft link
to `language_server.sh`.

I don't have a linux computer, so I don't know what the command is on
Linux.

Should we use a unified name in Eglot like `elixir-ls` (which is the
user's job to name their elixir's lsp), or keep using `language_server`,
which may leading to conflict on system wide.

I guess the best way to solve this is to let elixir-ls's dev rename
their release :)