[LyX/master] Python 3.13 removed the pipes module from the standard library

[José Matos]

On Sun, 2024-08-25 at 10:20 +0100, José Matos wrote:
> @Riki candidate for 2.4.2.
> 
> This change seems straightforward but, as usual, things can go wrong.
> :-)
> 
> Best regards,

Done after getting the nod from Riki.

FWIW this code needs a shell so it is only used for unix-like systems.

-- 
José Abílio