properly track delegated host in loops

ansible_host can be pulled from inventory and not match inventory_hostname,
this can "loose" vars to a new host named by ansible_host vs the delegated host
fixes #25770

lib/ansible/executor/task_executor.py

@@ -628,7 +628,7 @@ class TaskExecutor:
         delegated_vars = variables.get('ansible_delegated_vars', dict()).get(self._task.delegate_to, dict()).copy()
         if len(delegated_vars) > 0:
             result["_ansible_delegated_vars"] = dict()
-            for k in ('ansible_host', ):
+            for k in ('ansible_delegated_host', 'ansible_host' ):
                 result["_ansible_delegated_vars"][k] = delegated_vars.get(k)
 
         # and return

lib/ansible/plugins/strategy/__init__.py

@@ -245,7 +245,7 @@ class StrategyBase:
         return host_list
 
     def get_delegated_hosts(self, result, task):
-        host_name = result.get('_ansible_delegated_vars', {}).get('ansible_host', None)
+        host_name = result.get('_ansible_delegated_vars', {}).get('ansible_delegated_host', None)
         if host_name is not None:
             actual_host = self._inventory.get_host(host_name)
             if actual_host is None:

lib/ansible/vars/manager.py

@@ -524,7 +524,8 @@ class VariableManager:
                 new_port = 5986
 
             new_delegated_host_vars = dict(
-                ansible_host=delegated_host_name,
+                ansible_delegated_host=delegated_host_name,
+                ansible_host=delegated_host_name, #  not redundant as other sources can change ansible_host
                 ansible_port=new_port,
                 ansible_user=C.DEFAULT_REMOTE_USER,
                 ansible_connection=C.DEFAULT_TRANSPORT,