GitLab CI object storage cache is broken

All our GitLab CI jobs seem to be failing to upload caches to the MinIO object storage bucket:

Uploading cache.zip to https://minio.torproject.org:9000/gitlab-ci-runner-cache/project/2302/default-non_protected 
FATAL: received: 403 Forbidden                     
Failed to create cache

This is probably related to the recent rotation of credentials.