math/py-numexpr: Update to 2.8.0
- Update MASTER_SITES: use GitHub temporarily due to format issue in sdist
> Extracting for py39-numexpr-2.8.0
> SHA256 Checksum OK for numexpr-2.8.0.tar.gz.
tar: Ignoring malformed pax extended attribute
tar: Error exit delayed from previous errors.
> Failed to extract "/usr/ports/distfiles//numexpr-2.8.0.tar.gz".
- Error code 1
Changes: https://github.com/pydata/numexpr/blob/master/RELEASE_NOTES.rst