**Apache Airflow version**: 2.0.1


**Kubernetes version (if you are using kubernetes)** (use `kubectl version`): No

**Environment**:

- **Cloud provider or hardware configuration**: local machine
- **OS** (e.g. from /etc/os-release): 18.04.5 LTS (Bionic Beaver)
- **Kernel** (e.g. `uname -a`): wsl2

**What happened**:
Getting Pickled_id: None

```
root@12c7fd58e084:/opt/airflow# airflow tasks run example_bash_operator runme_0 now --ship-dag --interactive
[2021-05-09 13:11:33,247] {dagbag.py:487} INFO - Filling up the DagBag from /files/dags
Running <TaskInstance: example_bash_operator.runme_0 2021-05-09T13:11:31.788923+00:00 [None]> on host 12c7fd58e084
Pickled dag <DAG: example_bash_operator> as pickle_id: None
Sending to executor.
[2021-05-09 13:11:34,722] {base_executor.py:82} INFO - Adding to queue: ['airflow', 'tasks', 'run', 'example_bash_operator', 'runme_0', '2021-05-09T13:11:31.788923+00:00', '--local', '--pool', 'default_pool', '--subdir', '/opt/airflow/airflow/example_dags/example_bash_operator.py']
[2021-05-09 13:11:34,756] {local_executor.py:81} INFO - QueuedLocalWorker running ['airflow', 'tasks', 'run', 'example_bash_operator', 'runme_0', '2021-05-09T13:11:31.788923+00:00', '--local', '--pool', 'default_pool', '--subdir', '/opt/airflow/airflow/example_dags/example_bash_operator.py']
[2021-05-09 13:11:34,757] {local_executor.py:386} INFO - Shutting down LocalExecutor; waiting for running tasks to finish.  Signal again if you don't want to wait.
[2021-05-09 13:11:34,817] {dagbag.py:487} INFO - Filling up the DagBag from /opt/airflow/airflow/example_dags/example_bash_operator.py
Running <TaskInstance: example_bash_operator.runme_0 2021-05-09T13:11:31.788923+00:00 [None]> on host 12c7fd58e084
```

**What you expected to happen**:

Pickled_id should get generated 

```
Pickled dag <DAG: example_bash_operator> as pickle_id: None
```

**How to reproduce it**:
run below command from command line in airflow environment
```
airflow tasks run example_bash_operator runme_0 now --ship-dag --interactive
```
**Would like to submit PR for this issue**: YES


airflow/cli/commands/task_command.py
"""
    Trying to guess the debugger used by the user. When it doesn't find any user-installed debugger,
    returns ``pdb``.
    List of supported debuggers:
    * `pudb <https://github.com/inducer/pudb>`__
    * `web_pdb <https://github.com/romanvm/python-web-pdb>`__
    * `ipdb <https://github.com/gotcha/ipdb>`__
    * `pdb <https://docs.python.org/3/library/pdb.html>`__
    """
    for mod in SUPPORTED_DEBUGGER_MODULES:
        try:
            return importlib.import_module(mod)
        except ImportError:
            continue
    return importlib.import_module("pdb")
@cli_utils.action_logging
@suppress_logs_and_warning
@provide_session
def task_states_for_dag_run(args, session=None):
    """Get the status of all task instances in a DagRun"""
    dag_run = (
        session.query(DagRun)