chore: revise the CI/CD pipeline functionality in configs and noxfile

[chalmerlowe]

Several changes were made in the python-bigquery library that I would like to see replicated here:

• Ensure that each major session in the noxfile.py has a session.run("python", "-m", "pip", "freeze") expression.
• If necessary, remove any extraneous expressions that produce version numbers (ie. print(pandas.__version__)) since they will be handled by the more robust pip freeze expression.
• Remove os.environ.get("RUN_SYSTEM_TESTS") style expressions based on checking variable values in deference to using fine grained config files. See this python-bigquery PR # 1915 for an example. (NOTE: there will also need to be some changes done in google3 internally)
• Revise the config files to separate out specific nox.sessions for parallel processing. Candidates include presubmit/linting-typing.cfg, presubmit/snippets, continuous/python-3.9 to 3.11) There may be several others. See here for an example.
• Add a @_calculate_duration decorator to each nox.session to allow us to monitor how long each session actually takes. See this PR #1917 for an example.