### Summary

The config option `options.display_skipped_hosts.env.0` should be removed from `lib/ansible/plugins/callback/default.py`. It was scheduled for removal in 2.12.

### Issue Type

Bug Report

### Component Name

`lib/ansible/plugins/callback/default.py`

### Ansible Version

2.14

### Configuration

N/A

### OS / Environment

N/A

### Steps to Reproduce

N/A

### Expected Results

N/A

### Actual Results

N/A
version_added: '2.9'
      check_mode_markers:
        name: Show markers when running in check mode
        description:
        - Toggle to control displaying markers when running in check mode.
        - "The markers are C(DRY RUN) at the beginning and ending of playbook execution (when calling C(ansible-playbook --check))
        and C(CHECK MODE) as a suffix at every play and task that is run in check mode."
        type: bool
        default: no
        version_added: '2.9'
        env:
          - name: ANSIBLE_CHECK_MODE_MARKERS
        ini:
          - key: check_mode_markers
            section: defaults
      show_task_path_on_failure:
        name: Show file path on failed tasks
        description:
          When a task fails, display the path to the file containing the failed task and the line number.
          This information is displayed automatically for every task when running with C(-vv) or greater verbosity.
        type: bool
        default: no
        env:
          - name: ANSIBLE_SHOW_TASK_PATH_ON_FAILURE
        ini:
          - key: show_task_path_on_failure
            section: defaults
        version_added: '2.11'
'''