Is your feature request related to a problem? Please describe.

In #6505, we decided to keep the title and description of filter blocks in both index and metadata files to keep the translation for those fields working as expected during the transition phase. Once the new language packs have been updated, we should remove the title and description from the index file.

Describe the solution you'd like

We should remove duplicated strings after the version of WC Blocks containing refactored filter blocks is merged into the WC core.