Fix pip uncap fallout for nova and barbican

Need to make PyYAML overridable on Ubuntu, it is a dependency for e.g.
cloud-init, so we cannot remove it.

Depends-On: https://review.opendev.org/703792
Change-Id: I4423dfb2c30299903b52a2bb06d846dd487f5b8b

tools/fixup_stuff.sh

@@ -82,6 +82,14 @@ function fixup_ubuntu {
 
     # Enable universe
     sudo add-apt-repository -y universe
+
+    # Since pip10, pip will refuse to uninstall files from packages
+    # that were created with distutils (rather than more modern
+    # setuptools).  This is because it technically doesn't have a
+    # manifest of what to remove.  However, in most cases, simply
+    # overwriting works.  So this hacks around those packages that
+    # have been dragged in by some other system dependency
+    sudo rm -f /usr/lib/python3/dist-packages/PyYAML-*.egg-info
 }
 
 # Python Packages