NatLibFi/Annif: Annif 0.55

This release includes a new language filtering feature. This input-transform filters out sentences of the intput text whose language is different than the project language. The language detection is performed with Compact Language Detector v3 via pycld3. pycld3 is an optional dependency of Annif, see the installation page. Also minor bug fixes and dependency updates are included. The Maui and vw_multi (Vowpal Wabbit) backends have been marked as deprecated in this release and they will be removed in the next release 0.56. Removing is motivated by making codebase more compact and thus easier to maintain. The MLLM and nn_ensemble backends offer similar functionality as Maui and vw_multi. Note that the notes for the previous release (Annif 0.54) initially missed to mention the added support for the input-transform feature. New features: 464/#507 Language filtering in input text Improvements: 536 Allow rdflib version 6.* Bug fixes: 533/#534 Adjust flask and click versions to avoid dependency mismatches Maintenance: 530 Add deprecation warning to Maui & vw_multi train commands 492/#529 Update Docker base image to Debian Bullseye to upgrade Voikko librar