fix: double check that an MR is not wip before assigning

it seems that filtering in the search is not enough, and some MR may be wip,
even when the 'wip="no"' parameter is given.

Let' skip WIP merge requests

assignbot/__main__.py

@@ -162,6 +162,12 @@ class ReviewAssigner:
         shuffle(merge_requests)
 
         for merge_request in merge_requests:
+            if merge_request.work_in_progress:
+                # double check that the MR is not WIP.
+                # it seems that filtering in the search parameters is not enough
+                # XXX is it a bug ?
+                continue
+
             project = self.cnx.projects.get(merge_request.project_id)
             if CLIENT_PROJECT_TAG in project.tag_list:
                 # it's a client project. Let's assume that someone will take