repo:voltha-docs - problem with jenkins:lint and local make html (python 3.5)

A commit for repo:voltha-docs encountered a few problems:

Problem #1: Source edits triggered unrelated lint failures.

1. Unclear how this state came to be, a commit to introduce these changes should have triggered the same failures below.
   1. Is this a one-off dependency problem ?  Commit modifying code is accepted but every job afterward is doomed to fail until issues are resolved.
   2. Was (enhanced?) linting enabled after problems were introduced  and existing problems still need to be cleaned up ?
   3. Merge directly into master could do this but access should be a problem.

Problem #2 Devs cannot use "make html" to pre-screen local edits for problems.

• jenkins environment has interpreter and packages frozen on v3.5 or v3.6
• Python v3.8 -> 3.11 are generally available to a user/OS install but are currently unusable
• make html
  • ImportError: cannot import name 'Mapping' from 'collections' (/opt/python/3.10.6/lib/python3.10/collections/__init__.py)

Problem #3: "make lint" exhibits different behavior locally VS jenkins:

• Suspect this may be due to 'handle warnings as error'.
• "make lint" locally using python 3.10.6 succeeds
  • Total files scanned = 39
    Total files ignored = 0
    Total accumulated errors = 0

• Jenkins fails outright

https://jenkins.opencord.org/job/verify_voltha-docs_unit-test/322/console
15:12:57 checking consistency... /w/workspace/verify_voltha-docs_unit-test/voltha-docs/venv_docs/lib/python3.6/site-packages/recommonmark/parser.py:75: UserWarning: Container node skipped: type=document
15:12:57 /w/workspace/verify_voltha-docs_unit-test/voltha-docs/howto/voltha_repositories.rst: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/openolt/BUILDING.md: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/openolt/SECURITY.md: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/openolt/olt-sw-upgrade/README.md: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/readme.rst: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/voltctl/MULTIPLE_STACKS.md: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/voltha-openonu-adapter-go/templates/README.md: WARNING: document isn't included in any toctree*15:12:57* /w/workspace/verify_voltha-docs_unit-test/voltha-docs/voltha-system-tests/tests/data/onos-files/README.md: WARNING: document isn't included in any toctree
 

At the very least "make lint" should have consistent behavior wherever used.