FTBFS: checksum mismatch; upstream retagged

Description:

==> Validating source files with sha512sums...
    scons ... FAILED
    SCons-4.9.1.tar.gz ... FAILED
==> ERROR: One or more files did not pass the validity check!

Upstream retagged from 2758b85 to dfd6b7e[1], with only documentation changes.

Additional info:

• package version(s): 4.9.1-1

Steps to reproduce:

1. extra-x86_64-build

[1] https://github.com/SCons/scons/commits/4.9.1/