This commit changes the Github Actions workflow configuration to use
an older version of Ubuntu for testing on Python 3.5 and 3.6 - namely
Ubuntu 20.04 instead of the current default 22.04. The runners that
Github provides with Ubuntu 22.04 don't support versions of Python
prior to 3.7.

We will remove support for Python <3.7 at some point, when a code change
makes it necessary, but for now there happens to be nothing in the code
that breaks with Python 3.5 or 3.6 and it's easy enough to support those
versions, which is why I'm not removing support for them entirely yet.

I also upgraded the workflow configuration from the beta version of
Python 3.11 to the final release version.

Replace the _stop method, which was removed from aiosmtp 1.4.3, with the cancel_tasks method

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Use older Ubuntu for testing with Python 3.5 and 3.6

This commit updates the pre-commit configuration to use a newer version
of the GitHub actions linter, which gives better error messages for
workflows involving environments.

In this commit I'm adding a new workflow which will build distributable
packages for pytest-localserver and upload them to PyPI and Test PyPI.
The uploads are treated as deployments, so they will not run until
someone manually approves them.

A future enhancement I'd like to make is to actually run tests using
the same package that is going to be uploaded. That's going to involve
tweaking tox to install from a prebuilt package rather than directly
from the source code, so it will take some time to figure that out.

…1/dev

Mark the package as being compatible with Python 3.11

Now that we have an automatic flow for making releases and uploading to
PyPI (and Test PyPI), I'm updating the instructions in the README file
to reflect it instead of the manual release flow that we used to use.

We haven't been updating the AUTHORS file as various people have added
their contributions to the project, so in this commit I'm catching up on
those updates. It's important for both legal and ethical reasons that
everyone gets appropriate credit for their contributions.

I've taken the list of authors from the commit history. The list of
authors in the file is ordered chronologically by their first commit or
first interaction with the project (as far as I'm aware), which seems
consistent with the order that was there before.

Update the AUTHORS file

…/dev

Release using GitHub actions

Update changelog for the upcoming 0.7.1 release