bzlmod migration

[zffchen]

What's the plan for adding MODULE.bazel support?

Ref: https://bazel.build/external/migration

[hawkinsp]

Well, it's mostly up to our dependencies (XLA) migrating. That may take a while given that is also entangled with TensorFlow.

[vam-google]

@zffchen tl;dr; the bzlmod upgrade is work in progress and is pretty much one of our priorities for this quarter.

The jax's move to bazel 7.4.1 was done exactly in the context of bazelmod migration effort. The upgrade got blocked by protobuf update, because it is pretty much impossible to migrate without upgrading porotobuf first. The protobuf upgrade is in progress here openxla/xla#25757. It already works for TF, and yesterday I finally had a chance to work on fixing the xla-specific failures and will be updating the PR soon. Once the update is pushed to all of our core repositories we'll resume bzlmod migration effort which will probably take 1-2 months.