text: Title: Tox v4 does not consistently require to escape the #
  Body: ## Issue
  
  Using this in `deps`:
  ```
  pylint-guidelines-checker @ git+https://github.com/Azure/azure-sdk-for-python#subdirectory=scripts/pylint_custom_plugin
  ```
  
  works like a charm, but I was assuming I should escape based on the tox v4 updating doc to:
  
  ```
  pylint-guidelines-checker @ git+https://github.com/Azure/azure-sdk-for-python\#subdirectory=scripts/pylint_custom_plugin
  ```
  
  But this one actually crashes tox. My CI unfortunately didn't kept the log, but the message is something like `cannot clone https://github.com/Azure/azure-sdk-for-python\` (note the `\` at the end). If that matters, I can re-crash my CI on purpose to get the real error message.
  
  I expect that when the tox updating doc says "The hash sign (#) now always acts as comment within tox.ini", then it's the case.
  
  
  ## Environment
  
  Provide at least:
  
  - OS: Linux or Windows
  - `pip list` of the host Python where `tox` is installed:
  
  ```console
  Jinja2-3.1.2 MarkupSafe-2.1.2 astroid-2.13.3 attrs-22.2.0 autorest-0.1.0 black-22.12.0 cachetools-5.3.0 chardet-5.1.0 click-8.1.3 colorama-0.4.6 dill-0.3.6 distlib-0.3.6 docutils-0.19 exceptiongroup-1.1.0 filelock-3.9.0 importlib-metadata-6.0.0 iniconfig-2.0.0 invoke-2.0.0 isort-5.11.4 json-rpc-1.14.0 lazy-object-proxy-1.9.0 m2r2-0.3.3 mccabe-0.7.0 mistune-0.8.4 mypy-0.991 mypy-extensions-0.4.3 nodeenv-1.7.0 packaging-23.0 pathspec-0.10.3 platformdirs-2.6.2 pluggy-1.0.0 ptvsd-4.3.2 pylint-2.15.10 pyproject-api-1.5.0 pyright-1.1.287 pytest-7.2.1 pyyaml-6.0 tomli-2.0.1 tomlkit-0.11.6 tox-4.3.5 typed-ast-1.5.4 types-PyYAML-6.0.12.3 typing-extensions-4.4.0 virtualenv-20.17.1 wrapt-1.14.1 zipp-3.11.0
  
  ```
  
  I'm not blocked since I removed the backslah and it works.