[Bazel CI] ERROR migrate to bzlmod

[sgowroji]

CI: https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/4093#0191abc3-fcd0-4666-81cc-70fb8587acec

Platform: Ubuntu

Logs:

ERROR: �[0merror loading package 'external': Both --enable_bzlmod and --enable_workspace are disabled, but one of them must be enabled to fetch external dependencies.

Culprit: bazelbuild/bazel@5881c38

Note : This issue is due to bazelbuild/bazel#23023. After --enable_workspace is flipped to false, users have to explicitly specify it where it's needed, or fully migrate to Bzlmod.

CC Greenteam @fweikert