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

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

Setuptools v82.0.0 removed the bundled pkg_resources module entirely.
This breaks RTD builds because sphinxcontrib-blockdiag (and
sphinxcontrib-seqdiag via blockdiag) import pkg_resources at the
module level, causing:

  ModuleNotFoundError: No module named 'pkg_resources'

Pin setuptools>=65.0.0,<82 in the docs requirements and example
templates to ensure pkg_resources remains available at build time.
Both sphinxcontrib-blockdiag and sphinxcontrib-seqdiag are
unmaintained (last released 2020) and cannot be patched upstream.

Long-term, these diagram extensions should be replaced with
actively maintained alternatives that use importlib.metadata.

Issue-ID: CIMAN-33
Change-Id: I3c5a81ee8ba562d7f0a06c1abc59015ca9003ba3
Signed-off-by: Matthew Watkins <mwatkins@linuxfoundation.org>