エラー: OpenVINO™・ツールキットで Ubuntu* 20.04 で「PyYAML をアンインストールできません」と表示される

• Ubuntu 20.04 にOpenVINO™・ツールキットをインストール
• Ran demo_squeezenet_download_convert_run.sh
• 以下のエラーが発生しました

Collecting pyyaml>=5.4.1
 Downloading PyYAML-5.4.1-cp38-cp38-manylinux1_x86_64.whl (662 kB)
   |████████████████████████████████| 662 kB 3.6 MB/s 
Requirement already satisfied: requests>=2.25.1 in /usr/local/lib/python3.8/dist-packages (from -r /opt/intel/openvino_2021/deployment_tools/demo/../open_model_zoo/tools/downloader/requirements.in (line 2)) (2.26.0)
Requirement already satisfied: urllib3<1.27,>=1.21.1 in /usr/local/lib/python3.8/dist-packages (from requests>=2.25.1->-r /opt/intel/openvino_2021/deployment_tools/demo/../open_model_zoo/tools/downloader/requirements.in (line 2)) (1.26.7)
Requirement already satisfied: charset-normalizer~=2.0.0 in /usr/local/lib/python3.8/dist-packages (from requests>=2.25.1->-r /opt/intel/openvino_2021/deployment_tools/demo/../open_model_zoo/tools/downloader/requirements.in (line 2)) (2.0.6)
Requirement already satisfied: certifi>=2017.4.17 in /usr/lib/python3/dist-packages (from requests>=2.25.1->-r /opt/intel/openvino_2021/deployment_tools/demo/../open_model_zoo/tools/downloader/requirements.in (line 2)) (2019.11.28)
Requirement already satisfied: idna<4,>=2.5 in /usr/lib/python3/dist-packages (from requests>=2.25.1->-r /opt/intel/openvino_2021/deployment_tools/demo/../open_model_zoo/tools/downloader/requirements.in (line 2)) (2.8)
Installing collected packages: pyyaml
 Attempting uninstall: pyyaml
  Found existing installation: PyYAML 5.3.1
ERROR: Cannot uninstall 'PyYAML'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.
Error on or near line 149; exiting with status 1

1. 次のコマンドを実行して、デフォルトの PyYAML 5.3.1 パッケージをアンインストールします。
   
    apt-get purge python3-yaml
    
2. デモスクリプトを 1 回実行します。
   
   .//deployment_tools/demo/demo_squeezenet_download_convert_run.sh