Log Message:
x11/py-sip6: Strengthen needing to test with qgis and annotate patch

The 6.8.0 release was very broken.  It built and packaged, but
generated code that doesn't build.  Thus, it's clear that new sip
releases need to be used to build-test demanding sip users, and so far
the most demanding user seems to be qgis.  This testing appears not to
have been done upstream.  Include a caution about .0 releases of sip,
based on this experience.

Annote a patch as having been sent upstream, and note upstream's
decision to partially merge and partially explain that it is
incorrect.