Apologiesserver

* Final release; code is unmaintained going forward.
* Refactor the run script and pre-commit hooks to reduce duplication.
* Rework the GitHub Actions build process to pull out shared code.

* Remove support for Python 3.7.
* Upgrade to Poetry v1.2.0 and make related build process changes.
* Upgrade to Pylint v2.15.0 and make related changes to configuration
* Fix Pylint's configured class-attribute-naming-style to be snake_case.
* Add dependency caching to GitHub Actions workflow.
* Fix the GitHub Actions matrix build to properly target Windows and MacOS.
* Address annoying PyUnresolvedReferences warnings in PyCharm.

* Modernize usage of attrs library.

* Adjust the pyproject.toml include directive to limit what goes into wheel.
* Remove the Safety scanner from the pre-commit hooks and GitHub action.

* Minor tweaks to typos in comments.
* Run test suite with python-testdox for more verbose output.
* Adjust dependencies and build process to support Python 3.10.

* Standardize the format of the Apache v2 statement in LICENSE.