Log Message:
Updated www/py-pelican to version 4.5.0.

Upstream changes (no version published between 4.2.0 and 4.5.0):
* List registered plugins via pelican-plugins command
* Override settings via -e / --extra-settings CLI option flags
* Add settings for custom Jinja globals and tests
* Customize article summary ellipsis via SUMMARY_END_SUFFIX setting
* Customize Typogrify dash handling via new TYPOGRIFY_DASHES setting
* Support Unicode when generating slugs
* Support Asciidoc .adoc file generation in Pelican importer
* Improve user experience when pelican --listen web server is quit
* Improve Invoke tasks template
* Include tests in source distributions
* Switch CI from Travis to GitHub Actions
* Remove support for Python 2.7

Pkgsrc changes:
* package is now incompatible with lang/python27