Some python tests open an AF_UNIX socket. The AF_UNIX path is limited
to 108 bytes[1].
In order to avoid error about a too long AF_UNIX path, the AT fvtr will be
run in the /tmp directory.

[1] https://man7.org/linux/man-pages/man7/unix.7.html#BUGS

Signed-off-by: Erwan Prioul <[email protected]>