math/py-scipy: Update to version 1.4.1

Major changes since version 1.2.2:
https://github.com/scipy/scipy/releases/tag/v1.4.1
https://github.com/scipy/scipy/releases/tag/v1.4.0
https://github.com/scipy/scipy/releases/tag/v1.3.0

Approved by: python (swills)
Differential Revision: https://reviews.freebsd.org/D23447