Bazel finally added a external dependency management system, called "Bzlmod", a while back: https://bazel.build/external/overview
By now, Bzlmod is mature and the old system (WORKSPACE.bazel files) have been deprecated as of Bazel 8 and will be removed in Bazel 9: https://bazel.build/external/migration

It is time to migrate to future proof our code base. This issue is tracking that effort.

There is a related issue that tracks upgrading to Bazel 8: #516