Robocop 6.7.0

This release was entirely community driven, huge thanks for @p-zander, @pavezzo & others for discussing and implementing
new changes and fixes.

New too-long-variable-name rule (#1443)

New LEN32 too-long-variable-name rule which reports variables with names longer than 40 characters. Allowed length
can be configured with max_len parameter.

Fix importing custom formatters (#1446)

Using Robocop with custom formatter will no longer throw an error when importing from inside Python module::

robocop --custom-formatters formatpath.to.my.CustomFormatter --configure CustomFormatter.enabled=True

Fix AttributeError when importing dataclass with Python 3.12 (#1449)

Robocop should no longer throw AttributeError when using dataclasses in custom rules with Python 3.12.