Revert "manylinux: Update scikit-build from 0.8.1 to 0.9.0"

This reverts commit 8eecfca.

scikit-build still has an important regression as described in

  scikit-build/scikit-build#415

manylinux-common/install-python-packages.sh

@@ -2,5 +2,5 @@
 
 for PIP in /opt/python/*/bin/pip; do
   $PIP install --disable-pip-version-check --upgrade pip
-  $PIP install scikit-build==0.10.0
+  $PIP install scikit-build==0.8.1
 done