ci: add release workflow without pypa action

[consideRatio]

Closes #68 by adding a release workflow. Note that I'm currently suggesting that we stop using the PyPA action as it is pretty much a one-liner to do it manually.

What is done by the action is can be seen in the PyPA action can be seen in this script based on these default input variables using twine with the following --help message for the check and upload commands.

usage: twine upload [-h] [-r REPOSITORY] [--repository-url REPOSITORY_URL]
                    [-s] [--sign-with SIGN_WITH] [-i IDENTITY] [-u USERNAME]
                    [-p PASSWORD] [--non-interactive] [-c COMMENT]
                    [--config-file CONFIG_FILE] [--skip-existing]
                    [--cert path] [--client-cert path] [--verbose]
                    [--disable-progress-bar]
                    dist [dist ...]

positional arguments:
  dist                  The distribution files to upload to the repository
                        (package index). Usually dist/* . May additionally
                        contain a .asc file to include an existing signature
                        with the file upload.

optional arguments:
  -h, --help            show this help message and exit
  -r REPOSITORY, --repository REPOSITORY
                        The repository (package index) to upload the package
                        to. Should be a section in the config file (default:
                        pypi). (Can also be set via TWINE_REPOSITORY
                        environment variable.)
  --repository-url REPOSITORY_URL
                        The repository (package index) URL to upload the
                        package to. This overrides --repository. (Can also be
                        set via TWINE_REPOSITORY_URL environment variable.)
  -s, --sign            Sign files to upload using GPG.
  --sign-with SIGN_WITH
                        GPG program used to sign uploads (default: gpg).
  -i IDENTITY, --identity IDENTITY
                        GPG identity used to sign files.
  -u USERNAME, --username USERNAME
                        The username to authenticate to the repository
                        (package index) as. (Can also be set via
                        TWINE_USERNAME environment variable.)
  -p PASSWORD, --password PASSWORD
                        The password to authenticate to the repository
                        (package index) with. (Can also be set via
                        TWINE_PASSWORD environment variable.)
  --non-interactive     Do not interactively prompt for username/password if
                        the required credentials are missing. (Can also be set
                        via TWINE_NON_INTERACTIVE environment variable.)
  -c COMMENT, --comment COMMENT
                        The comment to include with the distribution file.
  --config-file CONFIG_FILE
                        The .pypirc config file to use.
  --skip-existing       Continue uploading files if one already exists. (Only
                        valid when uploading to PyPI. Other implementations
                        may not support this.)
  --cert path           Path to alternate CA bundle (can also be set via
                        TWINE_CERT environment variable).
  --client-cert path    Path to SSL client certificate, a single file
                        containing the private key and the certificate in PEM
                        format.
  --verbose             Show verbose output.
  --disable-progress-bar
                        Disable the progress bar.

usage: twine check [-h] dist [dist ...]

positional arguments:
  dist        The distribution files to check, usually dist/*

optional arguments:
  -h, --help  show this help message and exit

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[consideRatio]

@minrk, this has gone stale - do you consider this ready for a merge at this point @minrk ?

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[minrk]

Thanks for the reminder!