Reuse existing family hierarchy info.

cylc/flow/config.py

@@ -575,10 +575,6 @@ def __init__(
 
         self.mem_log("config.py: end init config")
 
-        self.namespaces: Dict[str, List[str]] = {}
-        for name in self.taskdefs:
-            self.namespaces[name] = self.taskdefs[name].namespace_hierarchy
-
     @staticmethod
     def _warn_if_queues_have_implicit_tasks(
         config, taskdefs, max_warning_lines

cylc/flow/task_pool.py

@@ -43,7 +43,6 @@
     filter_ids,
     filter_ids_2
 )
-from cylc.flow.network.resolvers import TaskMsg
 from cylc.flow.workflow_status import StopMode
 from cylc.flow.task_action_timer import TaskActionTimer, TimerFlags
 from cylc.flow.task_events_mgr import (
@@ -1259,9 +1258,8 @@ def release_held_tasks(self, items: Iterable[str]) -> int:
         # so only 'waiting' is valid as a state selector.
         future_matched: 'Set[Tuple[str, PointBase]]' = set()
         future_matched, unmatched_future = filter_ids_2(
-            self.tasks_to_hold,
-            items,
-            self.config.namespaces
+            self.tasks_to_hold, items,
+            self.config.runtime['linearized ancestors']
         )
         # Release matching tasks.
         for name, cycle in future_matched:

cylc/flow/task_proxy.py

@@ -20,7 +20,6 @@
 from copy import copy
 from typing import (
     Any,
-    Callable,
     Counter as TypingCounter,
     Dict,
     List,