pycadf: Release 4.0.0

pycadf library didn't have a release since Sep 8, 2020 (since it
moved to independent release model in [1]).
Kolla packages it in containers directly from git (to include some
new patches), which is not ideal for a library (since 3.1.1 is in
upper-constraints).

[1]: https://review.opendev.org/c/openstack/releases/+/779228

Change-Id: I8e111dfa1b1b973edbee683a18dba57363ec06df

deliverables/_independent/pycadf.yaml

@@ -5,3 +5,8 @@ team: keystone
 type: library
 repository-settings:
   openstack/pycadf: {}
+releases:
+  - version: 4.0.0
+    projects:
+      - repo: openstack/pycadf
+        hash: dcfda50d90ad3bb2c09f194c1b75476f2d21478e