This closes HTTP responses when no content reads are required, as
when requests are made in streaming mode, ``requests`` doesn't know
whether the caller may intend to later read content from a streamed
HTTP response object and holds the socket open.

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

- Add 'workflow_dispatch' target
- Force output to use colour
- Print traceback on error
- Use parallel building

This means that 'push' triggered workflows are not cancelled.

* continuous integration: add comment explaining PYTHONWARNINGS env var to main unit test workflow

* continuous integration: unit test workflow: report-but-do-not-fail
  when warnings about pkg_resources deprecation are encountered during
  docutils dependency installation

* continuous integration: unit test workflow: instead of reducing the
  severity of all DeprecationWarnings during docutils (non-dev)
  installation, apply two message filters - one each for the warnings
  encountered so far

* continuous integration: unit test workflow: add 'module' and 'line'
  fields for warning filters

Ref:
https://docs.python.org/3/library/warnings.html#describing-warning-filters


---------

Co-authored-by: Jean-François B <2589111+jfbu@users.noreply.github.com>

Fix several reference errors throughout the documentation and set
``nitpick_ignore`` in ``doc/conf.py``.

This means that CI tests will only fail if the 'known good' version
fails. If the latest version of Ruff fails, perhaps due to new
checks, CI will not fail overall, but the failures from the latest
version will be reported.

This is because I would like CI to succeed for a while in order to merge
some LaTeX patch.