Do not follow symlinks

Siril version: 1.0.6

Operating System: (K)Ubuntu 22.04.1

Description of the bug

I want to include "biases", "darks" and "flats" as symlinks:

When I try to execute "OSC_Preprocessing.ssf" in my working directory then the line "convert bias -out=../process" put the "process" folder to my symlink destination and the script fails, because "cd ../process" fails and it cannot find the "bias" sequence.

…

Expected result:

The script should not put the "process" folder to the symlink destination.