[PRQ#48163] Deletion Request for python2-mpmath

MarsSeed [1] filed a deletion request for python2-mpmath [2]: Nothing on AUR needs the legacy python2-sympy libraries (1.1 from 2017, 1.5 from 2019). Submitted them for deletion (PRQ#48161, PRQ#48162). Safe to drop this one as well. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/python2-mpmath/