devel/py-virtualenv: Fix build caused by conflicting dependencies

• Temporarly disable DOCS option due to the conflit between the docs build-dependency textproc/py-towncrier with textproc/py-towncrier23, which the other dependency py-sphinxcontrib-towncrier now depends on.
  
  I prefer to disable this option instead of changing the dependency to py-towncrier23 because a user may have already installed py-towncrier in the system for other reasons before updating.
  
  Other reference:
  
  https://github.com/sphinx-contrib/sphinxcontrib-towncrier/issues/92

• Bump PORTREVISION

PR: 280687