Fix(deps): Pin setuptools<82 to retain pkg_resources

Fix(deps): Pin setuptools<82 to retain pkg_resources

Setuptools v82.0.0 removed the bundled pkg_resources module.
This breaks RTD builds because sphinxcontrib-redoc imports
pkg_resources at the module level, causing:

  ModuleNotFoundError: No module named 'pkg_resources'

Pin setuptools>=65.0.0,<82 in docs requirements and tox.ini
to ensure pkg_resources remains available at build time.

The sphinxcontrib-redoc extension is unmaintained (last released
2020) but is actively used to generate OpenAPI/ReDoc pages for
all Policy component APIs. Replacing it requires a separate
migration effort.

Issue-ID: CIMAN-33
Co-Authored-By: Claude <noreply@anthropic.com>
Change-Id: I95c147913567caaf8f5070b61465c9db7cae64b5
Signed-off-by: Matthew Watkins <mwatkins@linuxfoundation.org>