PYTHON: Fix tox configuration for Python 2.7

[jenisys]

🤔 What's changed?

• Fixes a problem in DEVELOPMENT support when using tox for Python 2.7.
• Problem seems to be related to macOS 12 Monterey
  SEE: Virtualenv does not work correctly on python 2.7 from python.org and new macOS 12 Monterey pypa/virtualenv#2284
• Use special section in "tox.ini" and
  use "pip install --user ..." to fix the problem for now.
• Added "py27" to envlist config parameter again (now that it is usable again).

⚡️ What's your motivation?

Fix a problem for using tox -e py27 for running test in an isolated virtual-environment for Python 2.7.
This case was disabled during the latest when it was discovered.
The problem is fixed for now (until the real problem is fixed).

🏷️ What kind of change is this?

• 🐛 Bug fix (non-breaking change which fixes a defect)

♻️ Anything particular you want feedback on?

No.

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.