Update sip and build for Python 3.8

3 jobs for v1.9.8rc2 in 35 minutes and 22 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #187992
linux
build-linux

00:34:07

passed #187993
win
build-win

00:27:21

 
  Deploy
passed #187994
linux conda
deploy-stable

00:01:14