get rid of Denis Simon 2-descent?

[Vincent Delecroix]

Dear all,

We ship in Sage the Denis Simon GP script for 2-descent on elliptic
curves over number fields (see src/sage/ext_data/pari). It appears
that these scripts are not maintained by its author and prevent
Sage from upgrading to PARI 2.13.0, see ticket

https://trac.sagemath.org/ticket/30801

I am trying my best to get these GP scripts but, without help, I will
have to remove them for the next Sage version. If you feel like that
this will be a big loss for the future, please join the effort on
the ticket.

Best wishes
Vincent