Update translations levels (September 2021)

Introduction

With the implementation of the feature to show the translation coverage in the language selection dropdown, the translation levels need to be updated on a monthly cadence.

Proposal

Once the monthly merge of the new translations is complete, update the translation levels data from Crowdin.

Documentation

• https://docs.gitlab.com/ee/development/i18n/merging_translations.html#manually-update-the-translation-levels

ToDo

• Complete the regular monthly merge of translations from Crowdin. #338519 (closed)
• Get the translation levels (% approved words) from Crowdin.
• Create an MR to update the translation levels data.
• Associate that MR to this issue.
• Complete the MR.
• When done, clone this issue for the next milestone.