devel/py-tox: Fix RUN_DEPENDS

• Remove py-toml from RUN_DEPENDS (toml>=0.10.2;python_version<="3.6")
• Add PYTHON_REL check for py-tomli (tomli>=2.0.1;python_version>="3.7" and python_version<"3.11")
• Update version requirement of RUN_DEPENDS
• Bump PORTREVISION for dependency change

Reference: https://github.com/tox-dev/tox/blob/3.28.0/setup.cfg#L36-L46
Approved by: portmgr (blanket)
With hat: python