Update sushy-tools to latest

This migrates away from a custom fork of sushy-tools, which worked
around the booting issue described here:
https://storyboard.openstack.org/#!/story/2007689

This issue has been fixed, according to the following issue, so
this patchset migrates us back to upstream sushy-tools.
https://review.opendev.org/c/openstack/sushy-tools/+/733152

Change-Id: I421c9d267640720571ac6fa2341af5102afbafb2
Closes: #467

roles/apache-wsgi-sushy-emulator/tasks/backend.yaml

@@ -40,9 +40,7 @@
 
   - name: Install sushy-tools
     pip:
-      # TODO (dukov) Replace this with upstream sushy-tools once
-      # https://storyboard.openstack.org/#!/story/2007689 has fixed
-      name: git+https://github.com/dukov/sushy-tools.git@0.9.1
+      name: sushy-tools
       executable: pip3
 
   - name: Create a used wsgi will run with