workspaces_follow_focus: fix unknown workspaces handling

pyprland/plugins/workspaces_follow_focus.py

@@ -40,15 +40,15 @@ class Extension(Plugin):
         busy_workspaces = set(
             m["activeWorkspace"]["id"] for m in monitors if m["id"] != monitor["id"]
         )
-        # get workspaces info
-        workspaces = await hyprctlJSON("workspaces")
-        assert isinstance(workspaces, list)
-        workspaces.sort(key=lambda x: x["id"])
         cur_workspace = monitor["activeWorkspace"]["id"]
         available_workspaces = [
             i for i in self.workspace_list if i not in busy_workspaces
         ]
+        try:
             idx = available_workspaces.index(cur_workspace)
+        except ValueError:
+            next_workspace = available_workspaces[0]
+        else:
             next_workspace = available_workspaces[
                 (idx + increment) % len(available_workspaces)
             ]