Correct the current API version in README.md
The current API version is corrected in the README header.
We’ve updated our runner tagging system. If you’re using our shared runners for your CI pipelines, please review the new tags here: https://docs.mpcdf.mpg.de/bnb/220.html#new-tags-for-mpcdf-gitlab-runners
The old tags will remain valid until the end of February 2026.
The current API version is corrected in the README header.