Slovak is one of the languages with few rules (22 of them) and not a lot of activity. Slovak's maintainer, Zdenko Podobný, won't have time to be more active in the foreseeable future, so I've set Slovak to "unmaintained". If you know someone who might be interested to work on LT's support for Slovak, please ask them to join.
I have not followed LT for a while and thus I have not found this announcement here earlier - Daniel wrote to me about this situation directly, and I've agreed to become maintainer of the Slovak rules.
I have some experience with LT rules. I will try to clean up the existing first, since there are too many false positives. My second goal is to find some other contributors.