exp queue: remove dvc queue attach command

tests/unit/command/test_queue.py

@@ -1,5 +1,4 @@
 from dvc.cli import parse_args
-from dvc.commands.queue.attach import CmdQueueAttach
 from dvc.commands.queue.kill import CmdQueueKill
 from dvc.commands.queue.logs import CmdQueueLogs
 from dvc.commands.queue.remove import CmdQueueRemove
@@ -118,28 +117,6 @@ def test_experiments_status(dvc, scm, mocker):
     m.assert_called_once_with()
 
 
-def test_experiments_attach(dvc, scm, mocker):
-    cli_args = parse_args(
-        [
-            "queue",
-            "attach",
-            "exp1",
-            "-e",
-            "utf8",
-        ]
-    )
-    assert cli_args.func == CmdQueueAttach
-
-    cmd = cli_args.func(cli_args)
-    m = mocker.patch(
-        "dvc.repo.experiments.queue.local.LocalCeleryQueue.attach",
-        return_value={},
-    )
-
-    assert cmd.run() == 0
-    m.assert_called_once_with(rev="exp1", encoding="utf8")
-
-
 def test_queue_logs(dvc, scm, mocker):
     cli_args = parse_args(["queue", "logs", "exp1", "-e", "utf8", "-f"])
     assert cli_args.func == CmdQueueLogs