* Remove __metaclass__ = type.
for i in $(grep -REl '__metaclass__ = type' plugins/ tests/); do
sed -e '/^__metaclass__ = type/d' -i $i;
done
* Remove super arguments, and stop inheriting from object.
* Make all doc fragments, module utils, and plugin utils private.
* Remove some unused and no longer needed imports.
This hopefully also fixes the CI issues, which do not happen locally for me...
* Fix formatting.
* Try to make CI happy, again.
* Fix imports.
* Lint.
* Remove unicode text prefixes.
* Replace str.format() uses with f-strings.
* Replace % with f-strings, and do some cleanup.
* Fix wrong variable.
* Avoid unnecessary string conversion.
