Add connect to IPCMessageSubscriber's async_methods

Fixes saltstack#60049 by making sure an IPCMessageSubscriber that is wrapped by
SyncWrapper has a connect method that runs the coroutine rather than
returns a fugure.

salt/transport/ipc.py

@@ -639,6 +639,7 @@ class IPCMessageSubscriber(IPCClient):
 
     async_methods = [
         "read",
+        "connect",
     ]
     close_methods = [
         "close",

tests/pytests/unit/transport/test_ipc.py

@@ -0,0 +1,22 @@
+import pytest
+import salt.ext.tornado.iostream
+import salt.transport.ipc
+import salt.utils.asynchronous
+
+
+def test_ipc_connect_in_async_methods():
+    "The connect method is in IPCMessageSubscriber's async_methods property"
+    assert "connect" in salt.transport.ipc.IPCMessageSubscriber.async_methods
+
+
+def test_ipc_connect_sync_wrapped():
+    """
+    Ensure IPCMessageSubscriber.connect gets wrapped by
+    salt.utils.asynchronous.SyncWrapper.
+    """
+    puburi = "/tmp/noexist.ipc"
+    subscriber = salt.utils.asynchronous.SyncWrapper(
+        salt.transport.ipc.IPCMessageSubscriber, args=(puburi,), loop_kwarg="io_loop",
+    )
+    with pytest.raises(salt.ext.tornado.iostream.StreamClosedError):
+        subscriber.connect()