science/code_saturne: Remove dependency

There is a runtime dependency to sysutils/torque which is about to
expire. However in recent versions of code_saturne documentation there
is no mention of the this dependency. For more information:
https://www.code-saturne.org/documentation/8.1/doxygen/src/md__i_n_s_t_a_l_l.html

Approved by: portmgr (blanket)